as they conceive it, whether they be selfish, altruistic, loyal, spiteful, or masochistic.
Their behavior is forward-looking, and it is also consistent over time. In particu-
lar, they try as best they can to anticipate the uncertain consequences of
their actions. Forward-looking behavior, however, may still be rooted in the
past, for the past can exert a long shadow on attitudes and values.
Actions are constrained by income, time, imperfect memory and calculat-
ing capacities, and other limited resources, and also by the available oppor-
tunities in the economy and elsewhere. These opportunities are largely
determined by the private and collective actions of other individuals and