In the study of psychology, there is a methodology called behaviorism, which concerns itself over the behavior of humans and animals and allows for behavior to be predicted, given certain conditions. This has a lot of functions in economics, as, after all, economics is essentially the study of how individuals, groups, and organizations behave when given scarce resources in a market. Indeed, in the field of behavioral economics, psychology and microeconomic theory are combined to study how decisions are made by economic agents. Economic theory, then, is the sum of a number of assumptions about human behavior in a market on a large scale and is inextricably linked to psychology. Yet, what are these fundamental assumptions and what are they based upon?
The first and most basic assumption that economics relies upon is that humans assign varying degrees of value to goods and service and thus desire things of higher value. Though this is not the case if you’re a monk who relinquishes all attachments, in general, humans are assumed to be desiring beings. The prime motivation for any human is first the fulfillment of its needs then the acquisition of objects of value. Economics refers to this as demand and has developed a model that explains varying degrees of value in indifference curves, measuring an object or services value in terms of utility. As desiring beings, humans want what they do not have and the more they have of something, the less it is valued, which is expressed by the concept of marginal utility.
The second assumption is that humans want to maximize their value while reducing their costs. If successful, this is called profit. However, in any economic transaction, both buyer and seller are trying to profit the most, and so a middleground is found where both profit equally, which in economics is called an equilibrium. Economics measures how much each side profited with consumer and producer surplus. This second assumption is extremely important to psychology, especially in the practice of conditioning. The goal of operant conditioning is to manipulate value and cost in order to influence behavior. Positive reinforcement represents giving a desired value, which can be seen as profit, while negative reinforcement represents the removal of something of negative value, which can be seen as the removal of a cost. Positive and negative punishment work in this same way, as they either introduce a cost or remove value.
One can view that the majority of human behavior, at least, in a Western capitalist culture, is the result of applied economic concepts. Though not a proponent of capitalism, Marx based his theories on the assumption that economics was the root of human behavior and society. The practical uses of economic thought are many, yet, they nonetheless rely on the assumption that humans are rational beings. Often, the difference between theory and reality is a result of the failing of this assumption. While there are many predictable elements to human behavior that economics keys in on, there are always rogue elements that prove theory wrong. One might refer to this rogue element as free will or perhaps is the result of one party making an uninformed decision that proves unprofitable. For example, in the ultimatum game where two players must split a dollar bill, 50:50 seems a logical equilibrium but one player can demand more of the share or else refuse to trade, which rewards neither player. If one player is forced into a situation where their opponent receives 99 and they receive 1, the penny matters little to them, so they can refuse the deal and give their opponent nothing simply out of spite, when theoretically they should take whatever value is offered.
It is important to note that the range of these probabilities is somewhat limited because every economic transaction represents an agreement of two parties acting in self-interest. This variability is modeled well by supply and demand curves, which show that, even at the highest price, there might be a consumer willing to pay much more than the good is worth at equilibrium. Even then, it is difficult to predict and control an economy when human behavior often defies theory. Thus, when the assumption that humans are rational beings proves to be false on a grand scale, the dire results, to name a few, include bankruptcy, economic crisis, recession, inflation, and so on.