Economists typically assume that preferences are fixed-that people know what they like and how much they like it relative to all other things, and that this rank-ordering is stable over time. But this assumption has never been accepted by any other discipline. Economists are increasingly having difficulty arguing that the assumption is true enough to generate useful predictions and explanations. Indeed, law and economics scholars increasingly acknowledge that preferences are constructed, and that the law itself can help construct preferences. Still, (...) fixed preferences are often treated as a normative ideal: Even if people don't have fixed preferences, they should. Behavioral law and economics scholars offer approaches to deal with this normative shortcoming. My article argues that preference construction, properly understood, is not normatively undesirable. Having fixed preferences means having a complete and stable rank ordering of what we want that dictates our choices. But we often do not have such an ordering, and rationally so. My article argues instead for an alternative process-based, account of preference construction. Rather than having a complete rank ordering, we have ways of making choices. We construct narratives, using evaluative criteria against a backdrop of wants, desires and inclinations, some of which we rank order and some of which we do not. The evaluative criteria embed a consideration of transaction costs: critically, where a decision is not very consequential, a formulaic decision rule that permits a ready choice among roughly comparable alternatives may serve our purposes better than a more considered alternative-by-alternative assessment. Our wants, desires and inclinations are for both traditional objects of choice and higher order values and desires; they are both previously constructed and constructed and elicited in the choice-making process. My article makes the case for such an account's potential explanatory power, as well as its tractability. (shrink)