The central features of this paradigm are as follows.
1.People are constantly confronted with the necessity of
making choices – as consumers, workers, investors, parents, and in many other roles.
2.In making these choices, they try to do the best they can,
given the constraints they face-constraints of money, time, energy, and information.
3.Their choices are influenced by relative “prices”- using this term in its broadest sense to include not only money costs but time costs, psychic costs, alternative costs, and others.
4.Their choices may also be influenced by a host of other factors, such as religion, social class, physical and psychological needs, and external pressures, When we observe large-scale, systematic changes in behavior, however, a sensible research strategy is to Iook first to see if there have been changes in the constraints or in relative prices.