(1) What may be gained by applying concepts generalised from economics to methodological problems? The perspective of cost-benefit analysis ('CBA' for short) may help the researcher to see what sorts of questions he should take into account when dealing with particular methodological problems. This claim is supported by applying generalised CBA-thinking to two standard problems of methodology. (2) In the practice of research the handling of basic statements does not normally constitute any problem, and no conscious decision is involved. In (...) the methodological reconstruction the key questions are: 'How can a particular basic statement be criticised?' and 'What are the costs of defending a statement that is "problematic"?' The problem of the empirical 'base' is an investment problem: whether or not to invest time and effort into processing a particular basic statement into a falsifying hypothesis for the theory we wish to test. The valuation of the costs of rejecting or, as the case may be, of defending a basic statement, are objective. (3) With respect to theories, in basic science, the issue is not one of acceptance or rejection of a single theory, but rather of theory preference. Both the rational response to a falsification and rational theory preference are governed by CBA-considerations. The option for one of two competing theories is based upon a CBA where the valuation of benefits and costs is objective. Theory change is an objective process, at least in those fields, where theorising is closely controlled by empirical testing: the better theory drives out the less good theory. The costs of defending a theory that is less good than its competitor are mainly epistemic resources forgone. The use of CBA in methodology not only is compatible with Popper's position, but it may pay to view Popper's methodology as an application of CBA to epistemic situations. (shrink)