Standard models of portfolio investment rely on various statistical measures of dispersion. Such measures favor returns smoothed over all states of the world and penalize abnormally low as well as abnormally high returns. A model of portfolio investment based on the tradeoff between expected return and expected loss considers only abnormally low returns as undesirable. Such a model has a comparative advantage over other existing models in that a first-order stochastically dominant portfolio always has a higher expected (...) return and a lower expected loss. Expected return—expected loss model of portfolio investment can rationalize the equity premium puzzle. Two random variables are not comoving if there is at least one state of the world in which one random variable yields a positive return and the other—a negative return. Such random variables provide hedging benefits from diversification in portfolio investment according to the expected return—expected loss model. A special case of this model, when an investor linearly trade-offs expected returns and expected losses, is also a special case of the prospect theory when a decision-maker has a piece-wise linear value function without any probability weighting. (shrink)

Traditional portfolio selection models mainly obtain the optimized portfolio ratio by focusing on the prices of financial products. However, investors’ multiple preferences and risk appetites are also significant factors that should be taken into account. In consideration of these two factors simultaneously, we propose a double-hierarchy model in this paper. Specifically, the first hierarchy quantifies investors’ risk appetite based on a historical simulation method and probabilistic preference theory. This hierarchy can be utilized to describe investors’ variable risk appetites (...) and ensure the obtained investment ratios meet investors’ immediate risk requirements. Then, using the cross-efficiency evaluation principle, the optimal investment ratios can be derived by fusing investors’ multiple preferences and risk appetites in the second hierarchy. Lastly, an illustrative example about evaluating the 10 largest capitalized stocks on the Shenzhen Stock Exchange is given to verify the feasibility and effectiveness of our newly proposed model. We make the theoretical contribution to improve the traditional portfolio selection model, especially considering investors’ subjective preferences and risk appetite. Moreover, the proposed model can be practical for assisting investors with their investment strategies in real life. (shrink)

McEntire (1984) proved that, for a portfolio problem with independent assets, the generalized harmonic mean plays the role of a risk-free threshold. Based upon this property, he developed a criterion for including or excluding assets in an optimal portfolio, and he proved an ordering theorem showing that an optimal portfolio always consists of positive amounts of the assets with the largest mean values. Also, some commonly used utility functions were shown to satisfy the property that (...) the dominance of an asset over another is unaffected by the addition of other assets. In this paper we extend these results to the case where assets are dependent. (shrink)

This paper describes the admissible classes of parametric distribution functions of return portfolios and analyzes their consistency with the maximization of the expected utility. In particular, we present a general theory and a unifying framework with the following aims: (1) studying the implications of the classical market restrictions on the portfolio distributions; (2) establishing general rules of ordering, when the uncertain prospect depends by a finite number of parameters; (3) understanding how a dispersion measure has to be used, in (...) order to obtain the investors' optimal portfolios. (shrink)

Green innovation investments have rapidly grown since 2000. Green innovation indexes play important roles and are typically constructed by screening and indexing. However, Nobel Laureate Markowitz emphasizes portfolio selection instead of security selection and accentuates that “A good portfolio is more than a long list of good stocks.” Moreover, the screening-indexing strategies ignore that investors can take green innovation as an additional objective and thus gain additional utility. We consequently construct 3-objective portfolio selection for green innovation in (...) addition to variance and expected return. An efficient frontier of portfolio selection then extends to an efficient surface which is a panorama of the optimal variance, expected return, and expected green innovation. Investors thus fully envisage the trade-offs and enjoy the freedom of choosing preferred portfolios on the surface. In contrast, the screening-indexing strategies inflexibly leave investors with only one point. As the originality, we prove in a theorem that there typically exists a curve on the efficient surface so all portfolios on the curve dominate the green innovation index. We test the dominance by component stocks of China Securities Index 300 and obtain affirmative results out of sample. The results still hold in robustness tests. At last, we classify green innovation into categories, further model the categories by general k -objective portfolio selection, and still illustrate the dominance. Consequently, investors can consider and control each category. (shrink)

A probability forecast scored ex post using a probability scoring rule (e.g. Brier) is analogous to a risky financial security. With only superficial adaptation, the same economic logic by which securities are valued ex ante – in particular, portfolio theory and the capital asset pricing model (CAPM) – applies to the valuation of probability forecasts. Each available forecast of a given event is valued relative to each other and to the “market” (all available forecasts). A forecast is seen to (...) be more valuable the higher its expected score and the lower the covariance of its score with the market aggregate score. Forecasts that score highly in trials when others do poorly are appreciated more than those with equal success in “easy” trials where most forecasts score well. The CAPM defines economically rational (equilibrium) forecast prices at which forecasters can trade shares in each other’s ex post score – or associated monetary payoff – thereby balancing forecast risk against return and ultimately forming optimally hedged portfolios. Hedging this way offers risk averse forecasters an “honest” alternative to the ruse of reporting conservative probability assessments. (shrink)

In the financial markets, there is a well established portfolio optimization model called generalized mean-variance model (or generalized Markowitz model). This model considers that a typical investor, while expecting returns to be high, also expects returns to be as certain as possible. In this paper we introduce a new media optimization system based on the mean-variance model, a novel approach in media planning. After presenting the model in its full generality, we discuss possible advantages of the mean-variance paradigm, such (...) as its flexibility in modeling the optimization problem, its ability of dealing with many media performance indices – satisfying most of the media plan needs – and, most important, the property of diversifying the media portfolios in a natural way, without the need to set up ad hoc constraints to enforce diversification. (shrink)

This paper attempts to identify behavioral patterns and compare their average success considering several criteria of bounded rationality. Experimentally observed choice behavior in various decision tasks is used to assess heterogeneity in how individual participants respond to 15 randomly ordered portfolio choices, each of which is experienced twice. Treatments differ in granting probability information and in eliciting aspirations. Since in our setting neither other regarding concerns nor risk attitude matter and probability of the binary chance move is choice irrelevant, (...) categorizing decision types relies on parameter dependence and choice adaptations. We find that most participants reduce systematically sub-optimality when following the identified criteria. (shrink)

The optimal investment problem is studied for a continuous time incomplete market model. It is assumed that the risk-free rate, the appreciation rates, and the volatility of the stocks are all random; they are independent from the driving Brownian motion, and they are currently observable. It is shown that some weakened version of Mutual Fund Theorem holds for this market for general class of utilities. It is shown that the supremum of expected utilities can be achieved on a sequence (...) of strategies with a certain distribution of risky assets that does not depend on risk preferences described by different utilities. (shrink)

The paper argues for the need for Ukrainian companies' intellectual capital strategy development which, in turn, will significantly improve their efficiency and transfer to a new level of functioning. In this study we prove the dominance of intellectual capital strategy in the structure of modern enterprises' strategic portfolio. The authors have determined the following strategies for intellectual capital's development: as a means of achieving the objectives of the company, aimed at creation and efficient use of its intellectual resources; a (...) comprehensive program of action and the system of qualitative and quantitative measurement of replenish and upgrade the components of intellectual capital in accordance with the objectives of its development; a detailed comprehensive plan to ensure competitive advantage through interaction and balanced growth of all structural elements of intellectual capital. The article focuses on the multi-purposive nature of intellectual capital, which necessitates the formation of its portfolio strategies with different combinations of subordination. The main focus of the article is made on generalization and systematization types of expansion strategies for the development of intellectual capital by various classification features to justify the selection of strategies for optimal portfolio. In the proposed typology the following strategies are figured out: in terms of implementing the strategy ; the nature management ; the source of ; the method of obtaining ; the degree of change components ; the nature of the growth process ; by type of business process management ; the nature of use ; the type of innovation behavior ; a competitive position ; the object management ; the structure of intellectual capital. The analysis of the essential characteristics of intellectual capital strategies considered in the classification is made. The emphasis is put on dialectical, flexible sensemaking of presented strategies typologies, taking into consideration the fact of evolution strategies, weave and matrix blending of different classifications in practice. We exemplify our arguments by presenting various functional strategies that make implementation possible using classifications identified in intellectual capital's strategies. Additionally, it is substantiated that the primary, landmark system of classification for all other approaches is classification strategies based on intellectual capital structure. It is therefore proposed to use provided in the article systematization framework as a methodological basis for a comprehensive understanding of the prospects for improvement and use of firms' intellectual capital. (shrink)

Investment Science, Second Edition, provides thorough and highly accessible mathematical coverage of the fundamental topics of intermediate investments, including fixed-income securities, capital asset pricing theory, derivatives, and innovations in optimal portfolio growth and valuation of multi-period risky investments. Eminent scholar and teacher David G. Luenberger, known for his ability to make complex ideas simple, presents essential ideas of investments and their applications, offering students the most comprehensive treatment of the subject available. New to this edition Three new chapters: (...) Risk Management, Credit Risk, and Data and Statistics Updated content and expanded coverage of many topics, including the capital asset pricing model, projection pricing, the Black-Scholes equation, computational methods, real options, the characterization of volatility, parameter estimation, and portfolio design New exercises reflecting advances in theory and practice provide opportunities to explore a wide range of concepts. (shrink)

This paper presents a new decision theory for modelling choice under risk. The new theory is a two-parameter generalization of expected utility theory. The proposed theory assumes that a decision maker: behaves as if maximizing expected utility; but may experience disappointment when the utility of a lottery’s outcome falls short of the expected utility of the lottery; and may have a preference for gambling. The proposed theory can rationalize the fourfold pattern of risk attitudes; the common ratio effect and the (...) reverse thereof ; the Allais paradox in classical common consequence problems and the reverse Allais paradox—in common consequence problems with an even split of a probability mass; violations of the betweenness axiom; switching behavior in the Samuelson’s example; violations of ordinal, upper and lower cumulative independence ; and preference reversals between valuations and choice. In application to insurance, the theory can rationalize full insurance with an actuarially unfair premium and aversion to probabilistic insurance. In application to optimal portfolio investment, the theory can rationalize the equity premium puzzle. (shrink)

Motivated by the analysis of a general optimal portfolio selection problem, which encompasses as special cases an optimal consumption and an optimal debt-arrangement problem, we are concerned with the questions of how a personality trait like risk-perception can be formalized and whether the two objectives of utility-maximization and risk-minimization can be both achieved simultaneously. We address these questions by developing an axiomatic foundation of preferences for which utility-maximization is equivalent to minimizing a utility-based shortfall risk measure. (...) Our axiomatization hinges on a novel axiom in decision theory, namely the risk-perception axiom. (shrink)

In this paper, we consider the composition of an optimal portfolio made of two dependent risky assets. The investor is first assumed to be a risk-averse expected utility maximizer, and we recover the existing conditions under which all these investors hold at least some percentage of their portfolio in one of the assets. Then, we assume that the decision maker is not only risk-averse, but also prudent and we obtain new minimum demand conditions as well as intuitively (...) appealing interpretations for them. Finally, we consider the general case of investor’s preferences exhibiting risk apportionment of any order and we derive the corresponding minimum demand conditions. As a byproduct, we obtain conditions such that an investor holds either a positive quantity of one of the assets or a proportion greater than 50 %. (shrink)

Socially responsible investment has grown enormously and has expanded globally in recent years. It allows SRI investors to reduce their portfolio risk assumptions through international diversification. In this context, the aim of this paper is twofold to examine price and volatility linkages among the most representative SRI indexes for North America, Europe, and Asia-Pacific employing a multivariate approach and to provide the out-of-sample performance of an optimal portfolio constructed on the basis of time-varying return and volatility forecasts (...) from this specification approach. Our overall results show that using this technique, it is possible to reduce risk and out-perform the naïve rule, which is usually employed in this type of investment. These findings are relevant not only for academics but also for practitioners, especially for professional managers of SRI portfolios. (shrink)

Smart farming has largely been driven by productivity and efficiency aims, but there is an increasing awareness of potential socio-ethical challenges. The responsible research and innovation approach aims to address such challenges but has had limited application in smart farming contexts. Using smart dairying research and development in New Zealand as a case study, we examine the extent to which principles of RRI have been applied in NZ smart dairying development and assess the broader lessons for RRI application in smart (...) farming. We draw on insights from: a review of research on dairy technology use in NZ; interviews with smart dairying stakeholders; and the application of an analytical framework based on RRI dimensions. We conclude that smart dairying R&D and innovation activities have focused on technology development and on-farm use without considering socio-ethical implications and have excluded certain actors such as citizens and consumers. This indicates that readiness to enact RRI in this context is not yet optimal, and future RRI efforts require leadership by government or dairy sector organisations to fully embed RRI principles in the guidelines for large R&D project design. More broadly, enacting RRI in smart farming requires initial identification of RRI readiness in a given sector or country and devising a roadmap and coherent project portfolio to support capacity building for enacting RRI. Additionally, methods for operationalising RRI must be adapted to the context of the national or sectoral innovation system in which smart farming is being developed. (shrink)

Smart farming has largely been driven by productivity and efficiency aims, but there is an increasing awareness of potential socio-ethical challenges. The responsible research and innovation approach aims to address such challenges but has had limited application in smart farming contexts. Using smart dairying research and development in New Zealand as a case study, we examine the extent to which principles of RRI have been applied in NZ smart dairying development and assess the broader lessons for RRI application in smart (...) farming. We draw on insights from: a review of research on dairy technology use in NZ; interviews with smart dairying stakeholders; and the application of an analytical framework based on RRI dimensions. We conclude that smart dairying R&D and innovation activities have focused on technology development and on-farm use without considering socio-ethical implications and have excluded certain actors such as citizens and consumers. This indicates that readiness to enact RRI in this context is not yet optimal, and future RRI efforts require leadership by government or dairy sector organisations to fully embed RRI principles in the guidelines for large R&D project design. More broadly, enacting RRI in smart farming requires initial identification of RRI readiness in a given sector or country and devising a roadmap and coherent project portfolio to support capacity building for enacting RRI. Additionally, methods for operationalising RRI must be adapted to the context of the national or sectoral innovation system in which smart farming is being developed. (shrink)

This article presents a review of the theoretical support of the Portfolio of Evidence as a pedagogical tool to be used at the higher level with the aim of improving writing products, understanding the importance of developing in students’ skills for the optimal construction of academic writings. The portfolio then becomes a resource used by teachers not only to obtain evidence of the progress of students in the subject that is developed, but also constitutes an indicator to (...) assess the progress in the acquisition of learning in the studentfrom the writings it produces. The particularity of being continuous and progressive also allows the student to self-assess their progress through the writing they make and can generate strategies for continuous improvement. (shrink)

Stochasticity and ambiguity are two aspects of uncertainty in economic problems. In the case of investments in risky assets, this uncertainty is manifested in the uncertainty of future returns. On the contrary, the complexity of the economic phenomenon itself and the ambiguity inherent in human thinking and judgment are characterized by indistinct boundaries. For the same problem, research from different perspectives can often provide us with more comprehensive and systematic information. Currently, the expected value of return or the variance representing (...) risk is still used as a rational investment criterion for both single-stage portfolios and multistage portfolios. However, in general, the greater the expected return of an investor, the greater the risk he should take. Different investors have different requirements for profitability, but regardless of their expected return, they always hope to find a set of portfolios that maximize the probability of achieving the expected rate of return. In this paper, after analyzing the development of portfolio investment theory research, we take fuzzy information processing as the entry point and systematically discuss the theory and methods of fuzzy modeling of portfolio investment decision-making from the perspective of fuzziness around the portfolio investment decision-making process. The results of the empirical analysis show that the existence of basis constraints affects investors’ investment strategies as well as their final returns, but there is a limit to the influence of basis constraints on portfolio performance, and investors can obtain optimal investment returns by selecting a reasonable number of securities to form a portfolio based on the characteristics of different securities. (shrink)

This paper weakens the expectation dependence concept due to Wright and its higher-order extensions proposed by Li to conform with the preferences generating the almost stochastic dominance rules introduced in Leshno and Levy. A new dependence concept, called excess dependence is introduced and studied in addition to expectation dependence. This new concept coincides with expectation dependence at first-degree but provides distinct higher-order extensions. Three applications, to portfolio diversification, to the determination of the sign of the equity premium in the (...) consumption-based CAPM, and to optimal investment in the presence of a background risk, illustrate the usefulness of the approach proposed in the present paper. (shrink)

This paper attempts to empirically assess how advice may reduce suboptimality in a portfolio choice experiment with risk-neutral participants induced via binary-lottery incentives. Previous studies with a larger set of choice tasks report overwhelming evidence of suboptimality and how it is slightly reduced by learning and experience. Participants confront 15 randomly ordered portfolio choices, which they experience again in 2 successive phases. Intermediate advice between phases alerts participants that less-risky investments can improve the outcome for at least one (...) chance event without harming their success chances in the other random event. Compared to the pure choice treatment, another cognitively more demanding treatment additionally asks participants to form event-specific success aspirations that allow us to test satisficing and its optimality. The results show that intermediate advice increases the share of satisficing but not of optimal behavior beyond learning through experience. However, it significantly lowers the average distance from optimality. (shrink)

With the continuous development of the stock market, designing a reasonable risk identification tool will help to solve the irrational problem of investors. This paper first selects the stocks with the most valuable investment value in the future through the random forest algorithm in the nine-factor model and then analyzes them by using the higher-order moment model to find that different investors’ preferences will make the weight of the portfolio change accordingly, which will eventually make the optimal return (...) and risk set of the composition of the portfolio change. The risk identification system designed in this paper can provide an effective risk identification tool for investors and help them make rational judgments. (shrink)

Web services are self-describing and self-contained modular applications based on the network. With the deepening of web service applications, service consumers have gradually increased their requirements for service functions and service quality. Aiming at how to select the optimal plan from a large number of execution plans with the same function and different QoS characteristics, this paper proposes a web service selection algorithm that supports QoS global optimization and dynamic replanning. The algorithm uses position matrix coding to represent all (...) execution paths and replanning information of the service combination. By calculating the Hamming distance of the service quality between individuals, the quality of the service portfolio is improved. By specifying the total user time limit and implementing a good solution retention strategy, the problem of the impact of algorithm running time on service quality is solved. The experimental results show that the method proposed in this paper is effectively integrated into the development trend of QoS and close to the requester’s needs and can better meet user needs. This algorithm improves the user’s satisfaction with the returned service to a certain extent and improves the efficiency of service invocation. (shrink)

Governments and non-govermental organizations (NGOs) that plan projects to conserve the environment and alleviate poverty often attempt to modify rural livelihoods by halting activities they judge to be destructive or inefficient and encouraging alternatives. Project planners typically do so without understanding how rural people themselves judge the value of their activities. When the alternatives planners recommend do not replace the value of banned activities, alternatives are unlikely to be adopted, and local people will refuse to participate. Human behavioral ecology and (...) behavioral economics may provide useful tools for generating and evaluating hypotheses for how people value economic activities in their portfolios and potential alternatives. This is demonstrated with a case example from southwestern Madagascar, where plans to create a Mikea Forest National Park began with the elimination of slash-and-burn maize agriculture and the encouragement to plant labor-intensive manioc instead. Future park plans could restrict access to wild tuber patches, hunting small game, and fishing. The value of these activities is considered using observational data informed by optimal foraging theory, and experimental data describing people’s time preference and covariation perception. Analyses suggest that manioc is not a suitable replacement for maize for many Mikea because the two crops differ in terms of labor requirements, delay-to-reward, and covariation with rainfall. Park planners should promote wild tuber foraging and stewardship of tuber patches and the anthropogenic landscapes in which they are found. To conserve small game, planners must provide alternative sources of protein and cash. Little effort should be spent protecting lemurs, as they are rarely eaten and never sold. (shrink)

Funding agencies and large public scientific institutions are increasingly using the term “research portfolio” as a means of characterizing their research. While portfolios have long been used as a heuristic for managing corporate R&D, they remain ill-defined in a science policy context where research is aimed at achieving societal outcomes. In this article we analyze the discursive uses of the term “research portfolio” and propose some general considerations for their application in science policy. We explore the use of (...) the term in private R&D and related scholarly literature in existing science policy practices, and seek insight in relevant literature in science policy scholarship. While the financial analogy can in some instances be instructive, a simple transposition from the world of finance or of corporate R&D to public research is problematic. However, we do identify potentially fruitful uses of portfolio analysis in science policy. In particular, our review suggests that the concept of research portfolio can indeed be a useful analytical instrument for tackling complex societal challenges. Specifically, the strands of scholarship identified suggest that the use of research portfolio should: i) recognize the diversity of research lines relevant for a given societal challenge, given the uncertainty and ambiguity of research outcomes; ii) examine the relationships between research options of a portfolio and the expected societal outcomes; and iii) adopt a systemic perspective to research portfolios – i.e. examine a portfolio as a functional whole, rather than as the sum of its parts. We argue that with these considerations, portfolio-driven approaches may foster social inclusion in science policy decisions, help deliberation between “alternative” portfolios to tackle complex societal challenges, as well as promote cost-effectiveness and transparency. (shrink)

One of the most prominent social influences on human decision making is conformity, which is even more prominent when the perceptual information is ambiguous. The Bayes optimal solution to this problem entails weighting the relative reliability of cognitive information and perceptual signals in constructing the percept from self‐sourced/endogenous and social sources, respectively. The current study investigated whether humans integrate the statistics (i.e., mean and variance) of endogenous perceptual and social information in a Bayes optimal way while estimating numerosities. (...) Our results demonstrated adjustment of initial estimations toward group means only when group estimations were more reliable (or “certain”), compared to participants’ endogenous metric uncertainty. Our results support Bayes optimal social conformity while also pointing to an implicit form of metacognition. (shrink)

How are “interesting” research problems identified and made durable by academic researchers, particularly in situations defined by multiple evaluation principles? Building on two case studies of research groups working on rare diseases in academic biomedicine, we explore how group leaders arrange their groups to encompass research problems that latch onto distinct evaluation principles by dividing and combining work into “basic-oriented” and “clinical-oriented” spheres of inquiry. Following recent developments in the sociology of valuation comparing academics to capitalist entrepreneurs in pursuit of (...) varying kinds of worth, we argue that the metaphor of the portfolio is helpful in analyzing how group leaders manage these different research lines as “alternative investment options” from which they were variously hoping to capitalize. We argue portfolio development is a useful concept for exploring how group leaders fashion “entrepreneurial” practices to manage and exploit tensions between multiple matrices of valuation and conclude with suggestions for how this vocabulary can further extend analysis of epistemic capitalism within science and technology studies. (shrink)

This article analyzes investors’ portfolio selection problems in a two-period dynamic model of Knightian uncertainty. We account for the existence of portfolio inertia in this two-period framework. Furthermore, by incorporating investors’ updating behavior, we analyze how observing new information in the first period will affect investors’ behavior. By this analysis, we show that observing new information in the first period will expand portfolio inertia in the second period compared with the case in which observing new information has (...) not been gained in the first period if the degree of Knightian uncertainty is sufficiently large. (shrink)

The pandemic had serious implications for university education, specifically due to the transition from face-to-face teaching to online methodologies. This article analyzes the perception of students undergoing speech therapy from a Chilean University about the E-portfolio incorporation as an evaluative tool during the emergency virtual teaching due to the COVID-19 pandemic. From quantitative research, a survey of 38 questions based on Likert scales was applied to 108 penultimate year undergraduate students. The survey demonstrated that there is an improvement in (...) the methodology and teaching support, as well as in the creativity and professionalism of the students. (shrink)

This project seeks to highlight the benefits of the implementation and management of the teaching digital portfolio. In today's world full of technology and tools that facilitate daily activities, education and its various processes must also embrace the digital tools available and make them the basis for any innovation and improvement process. The teaching portfolio in physics has long been the means by which teachers have organized the processes, evidence, and other results of educational work. Nowadays, all that (...) range of evidence and productions, which signify the achievement and advances in each group of students, has been able to be integrated into technology. (shrink)

Les photos de ce portfolio ont été prises par Philippe Carta, Julien Goetz, Francis Guermann, Bernard Muscat et Michel Noirez. Projecteur et enrouleur 35 mm mobiles installés dans le vestibule de l’Opéra-Théâtre pour la projection de Moïse et Aaron – 24 mars 2011. Avant la projection de Moïse et Aaron, Jean-Marie Straub, debout face à l’écran de l’Opéra-Théâtre, vérifie la qualité de l’image et du son. François Narboni et Régine Palucci présentent Moïse et Aaron. A...

The fate of optimality modeling is typically linked to that of adaptationism: the two are thought to stand or fall together (Gould and Lewontin, Proc Relig Soc Lond 205:581–598, 1979; Orzack and Sober, Am Nat 143(3):361–380, 1994). I argue here that this is mistaken. The debate over adaptationism has tended to focus on one particular use of optimality models, which I refer to here as their strong use. The strong use of an optimality model involves the claim that selection is (...) the only important influence on the evolutionary outcome in question and is thus linked to adaptationism. However, biologists seldom intend this strong use of optimality models. One common alternative that I term the weak use simply involves the claim that an optimality model accurately represents the role of selection in bringing about the outcome. This and other weaker uses of optimality models insulate the optimality approach from criticisms of adaptationism, and they account for the prominence of optimality modeling (broadly construed) in population biology. The centrality of these uses of optimality models ensures a continuing role for the optimality approach, regardless of the fate of adaptationism. (shrink)

Shareholders assume risk by investing. Sollars and Tuluca (2018) argue that while this does not justify a managerial policy of shareholder wealth maximization, it does justify compensating shareholders at the oftencalculated cost of equity—the cost that investors require given the level of risk they assume. Here, I show that this can be unfair if the cost of equity is unfair. I then show how shareholder wealth maximization as a managerial imperative is better justified on other grounds.

We analyze the comparative static effects of changes in the means, the standard deviations and the covariance of asset returns in a standard portfolio selection problem when investors have mean variance preferences. Simple and intuitive characterizations in terms of the elasticity of risk aversion are provided.

Although clinical ethics consultation is a high-stakes endeavor with an increasing prominence in health care systems, progress in developing standards for quality is challenging. In this article, we describe the results of a pilot project utilizing portfolios as an evaluation tool. We found that this approach is feasible and resulted in a reasonably wide distribution of scores among the 23 submitted portfolios that we evaluated. We discuss limitations and implications of these results, and suggest that this is a significant step (...) on the pathway to an eventual certification process for clinical ethics consultants. (shrink)

The propensity account of fitness intends to solve the classical tautologicity issue by identifying fitness with a disposition, the ability to survive and reproduce. As proponents recognized early on, this account requires operational independence from actual reproductive success to avoid circularity and vacuousness charges. They suggested that operational independence is achieved by measuring fitness values through optimality models. Our goal in this article is to develop this suggestion. We show that one plausible procedure by which these independent operationalizations could be (...) thought to take place, and which is in accordance with what is said in the optimality literature, is unsound. We provide two independent lines of reasoning to show this. We then provide a sketch of a more adequate account of the role of optimality models in evolutionary contexts and draw some consequences. (shrink)

The optimality approach to modeling natural selection has been criticized by many biologists and philosophers of biology. For instance, Lewontin (1979) argues that the optimality approach is a shortcut that will be replaced by models incorporating genetic information, if and when such models become available. In contrast, I think that optimality models have a permanent role in evolutionary study. I base my argument for this claim on what I think it takes to best explain an event. In certain contexts, optimality (...) and game-theoretic models best explain some central types of evolutionary phenomena. ‡Thanks to Michael Friedman, Helen Longino, Michael Weisberg, and especially Elliott Sober for comments on earlier drafts of this paper. †To contact the author, please write to: Department of Philosophy, Stanford University, Stanford, CA 94305-2155; e-mail: [email protected]. (shrink)

The background of this paper (section 1) consists in a new account to foundation‐theoretic epistemology characterized by two features: (i) All beliefs are to be justified by deductive, inductive or abductive inferences from a minimalistic class of unproblematic (introspective or analytic) basic beliefs. (ii) Higher‐order justifications for these inferences are given by means of the novel method of optimality justifications. Optimality justifications are a new tool for epistemology (section 2). An optimality justification does not attempt todemonstratethat a cognitive method is (...) reliable (which is impossible), but pursues the more modest goal of demonstrating that the method isoptimalamong all accessible alternative methods for the given epistemic goal. The reasoning from the established optimality of a method to the acceptability of a particular belief generated by the method is accomplished by so‐called optimality principles. In sections 3–5, the method of optimality justifications is carried out in detail for three fundamental problems: justifying induction, logic, and theory‐generating abduction. (shrink)

What constitutes enjoyment of life? Optimal Experience: Psychological Studies of Flow in Consciousness offers a comprehensive survey of theoretical and empirical investigations of the "flow" experience, a desirable or optimal state of consciousness that enhances a person's psychic state. "Flow" can be said to occur when people are able to meet the challenges of their environment with appropriate skills, and accordingly feel a sense of well-being, a sense of mastery, and a heightened sense of self-esteem. The authors show (...) the diverse contexts and circumstances in which flow is reported in different cultures (e.g. Japan, Korea, Australia, Italy), and describe its positive emotional impacts. They reflect on the concept of flow vis-à-vis modern social structures, historical phenomena, and evolutionary biocultural selection. The ways in which the ability to experience flow affects work satisfaction, academic success, and the overall quality of life are suggested; and the childrearing practices that result in the ability to derive enjoyment from life, considered. (shrink)

This article investigates how firms address the stability-change paradox inherent in sustainability transitions through the maintenance and utilization of a portfolio of sustainability-oriented partnerships. Drawing on a retrospective case study of Dong/Ørsted, a Danish energy company, we demonstrate the varying manifestations of the stability-change paradox during different phases of the company’s transition, influenced by both exogenous and endogenous factors. Furthermore, our findings reveal how Dong/Ørsted employed their partnership portfolio to implement diverse responses to manage the paradox. Based on (...) these findings, we argue that partnership portfolios can serve as spatiotemporal pockets, enabling organizations to effectively address and leverage the temporal and spatial aspects inherent in sustainability paradoxes. In addition, we highlight how partnership portfolios facilitate sustainability transitions by creating and leveraging different forms of collaborative value. (shrink)

We present here the “e-Portfolio” concept, which aims to provide access to documented design case studies of design researchers’ practices. Our e-Portfolio has its origins in Grounded Design. We examine here how the e-Portfolio concept grew out of Grounded Design, the way it instantiates values, and how it contributes to our understanding of the ways in which shifting values in practice can have an impact beyond the individual.

The Enhanced Indispensability Argument appeals to the existence of Mathematical Explanations of Physical Phenomena to justify mathematical Platonism, following the principle of Inference to the Best Explanation. In this paper, I examine one example of a MEPP—the explanation of the 13-year and 17-year life cycle of magicicadas—and argue that this case cannot be used defend the EIA. I then generalize my analysis of the cicada case to other MEPPs, and show that these explanations rely on what I will call ‘ (...) class='Hi'>optimal representations’, which are representations that capture all that is relevant to explain a physical phenomenon at a specified level of description. In the end, because the role of mathematics in MEPPs is ultimately representational, they cannot be used to support mathematical Platonism. I finish the paper by addressing the claim, advanced by many EIA defendants, that quantification over mathematical objects results in explanations that have more theoretical virtues, especially that they are more general and modally stronger than alternative explanations. I will show that the EIA cannot be successfully defended by appealing to these notions. (shrink)

The prevalence of optimality models in the literature of evolutionary biology is testimony to their popularity and importance. Evolutionary biologist R. C. Lewontin, whose criticisms of optimality models are considered here, reflects that "optimality arguments have become extremely popular in the last fifteen years, and at present represent the dominant mode of thought." Although optimality models have received little attention in the philosophical literature, these models are very interesting from a philosophical point of view. As will be argued, optimality models (...) are central to evolutionary thought, yet they are not readily accomodated by the traditional view of scientific theories. According to the traditional view, we would expect optimality models to employ general, empirical laws of nature, but they do not. Fortunately, the semantic view of scientific theories, a recent alternative to the traditional view, more readily accomodates optimality models. As we would expect on the semantic view, optimality models can be construed as specifications of ideal systems. These specifications may be used to describe empirical systems--that is, the specifications may have empirical instances. But the specifications are not empirical claims, much less general, empirical laws. Although philosophers have yet to discuss the general features and uses of optimality models, these topics have stimulated much recent discussion among evolutionary biologists. Their discussions raise a number of precautions concerning the proper use of optimality models. Moreover, many of their caveats can be interpreted as general reminders that 1) optimality models specify ideal systems whose empirical instantiations may be quite restricted, and that 2) optimality models should not be construed as general, empirical laws. As G. F. Oster and E. O. Wilson caution, "the prudent course is to regard optimality models as provisional guides to further empirical research and not necessarily as the key to deeper laws of nature." It seems, then, that the semantic view of theories is more sensitive to the nature and limitations of optimality models than is the more traditional view of theories. (shrink)

Griffiths and Tenenbaum (2006) asked individuals to make predictions about the duration or extent of everyday events (e.g., cake baking times), and reported that predictions were optimal, employing Bayesian inference based on veridical prior distributions. Although the predictions conformed strikingly to statistics of the world, they reflect averages over many individuals. On the conjecture that the accuracy of the group response is chiefly a consequence of aggregating across individuals, we constructed simple, heuristic approximations to the Bayesian model premised on (...) the hypothesis that individuals have access merely to a sample of k instances drawn from the relevant distribution. The accuracy of the group response reported by Griffiths and Tenenbaum could be accounted for by supposing that individuals each utilize only two instances. Moreover, the variability of the group data is more consistent with this small‐sample hypothesis than with the hypothesis that people utilize veridical or nearly veridical representations of the underlying prior distributions. Our analyses lead to a qualitatively different view of how individuals reason from past experience than the view espoused by Griffiths and Tenenbaum. (shrink)

In a recent paper, Potochnik (Biol Philos 24(2):183–197, 2009) analyses some uses of optimality modelling in light of the anti-adaptationism criticism. She distinguishes two broad classes of such uses (weak and strong) on the basis of assumptions held by biologists about the role and the importance of natural selection. This is an interesting proposal that could help in the epistemological characterisation of some biological practices. However, Potochnik’s distinction also rests on the assumption that all optimality modelling represent the selection dynamic (...) involved in the system of phenomena being considered. Since this assumption does not hold for models belonging to optimal foraging theory (OFT)—one of behavioural ecology’s important modelling traditions—Potochnik’s proposal has to be critically reappraised. In this paper, we briefly discuss what is optimality modelling and what it means for a model to represent a dynamic of selection or of evolution. Then, we demonstrate that OFT modelling is unable to represent either past or contemporary selection dynamics. In order to make this point, we carefully delineate the theory’s rationale. This allows us to identify and analyse the assumptions on which the theory is built, and to circumscribe precisely the role that natural selection plays in it. Next, we show that the distinction of weak and strong uses of optimality modelling is seriously weakened when OFT modelling is taken into account. More precisely, the distinction is either irrelevant (if the assumption that selection dynamics are represented in all optimality modelling is held) or of a modest utility (if the assumption is dropped). However, we suggest that Potochnik’s original proposal could be saved, and that it even constitutes a tool to appraise the marks left in the literature by the evolution of optimality modelling practices in the last four decades, provided that it is made into a tripartite distinction. (shrink)

This paper focuses on flows to emerging capital markets (ECMs) and examines the importance of corporate transparency and public governance in attracting portfolio flows to ECMs. This paper's empirical investigation centers on the hypothesis that ceteris paribus, ECMs with better quality accounting standards and good governance attract higher levels of portfolio equity and bond flows. To assess the incremental impact of each of these factors, a pooled time series, cross‐sectional model was econometrically tested for 17 ECMS over the (...) 1998–2002 time period. Our empirical analysis demonstrates a positive association between public governance, corporate transparency, and portfolio flows after controlling for other macroeconomic factors. The results suggest that good public governance and high accounting quality are important determinants of portfolio flows to ECMs. Finally, the paper establishes that while portfolio equity flows are significantly attracted to ECMs with strong democratic institutions, there is no significant association between portfolio bond flows and the presence of democratic institutions. (shrink)