1971 http://law-of-small-numbers.behaviouralfinance.net/

"The matching law ... views choice not as a single event or an internal process of the organism but as a rate of observable events over time. It states that instead of maximizing utility, the organism allocates its behavior over various activities in exact proportion to the value derived from each activity. It differs subtly but significantly from rational choice theory in its predictions of how people exert self-control, for example, how they decide whether to forgo immediate pleasures for larger but delayed rewards. It provides, through the primrose path hypothesis, a powerful explanation of alcohol and narcotic addiction. It can also be used to explain biological phenomena, such as genetic selection and foraging behavior, as well as economic decision making."

"The birds were presented with a choice between a constant foraging option that always provided three seeds and a variable option that provided either no seeds or six seeds with equal probability."

"Buyers in almost any market fall into one of two groups - those who are extremely loyal to their supplier and those who systematically 'search' for good bargains."

"In particular, the most frequent buyers (those who visit the market more than once a week), with very few exceptions, visit only one seller, while less frequent buyers visit several sellers."

In a coevolutionary process, buyers learn to become loyal as sellers learn to offer higher utility to loyal buyers, while these sellers, in turn, learn to offer higher utility to loyal buyers as they happen to realize higher gross revenues from loyal buyers.