- Consumer demand theory
Consumer demand theory relates preferences for the consumption of both goods and services to the consumption expenditures; ultimately, this relationship between preferences and consumption expenditures is used to relate preferences to consumer demand curves. The link between personal preferences, consumption and the demand curve is one of the most closely studied relations in economics. It is a way of analyzing how consumers may achieve equilibrium between preferences and expenditures by maximizing utility subject to consumer budget constraints.
- Production theory
Production theory is the study of production, or the economic process of converting inputs into outputs. Production uses resources to create a good or service that is suitable for use, gift-giving in a gift economy, or exchange in a market economy. This can include manufacturing, storing, shipping, and packaging. Some economists define production broadly as all economic activity other than consumption. They see every commercial activity other than the final purchase as some form of production.
- Cost-of-production theory of value
The cost-of-production theory of value states that the price of an object or condition is determined by the sum of the cost of the resources that went into making it. The cost can comprise any of the factors of production including labor, capital, or land and taxation. Technology can be viewed either as a form of fixed capital (e.g. an industrial plant) or circulating capital (e.g. intermediate goods).
In the mathematical model for the cost of production, the short-run total cost is equal to fixed cost plus total variable cost. The fixed cost refers to the cost that is incurred regardless of how much the firm produces. The variable cost is a function of the quantity of an object being produced. The cost function can be used to characterize production through the duality theory in economics, developed mainly by Ronald Shephard (1953, 1970) and other scholars (Sickles & Zelenyuk, 2019, ch.2).
- Opportunity cost
Opportunity cost is closely related to the idea of time constraints. One can do only one thing at a time, which means that, inevitably, one is always giving up other things. The opportunity cost of any activity is the value of the next-best alternative thing one may have done instead. Opportunity cost depends only on the value of the next-best alternative. It doesn’t matter whether one has five alternatives or 5,000.
Opportunity costs can tell when not to do something as well as when to do something. For example, one may like waffles, but like chocolate even more. If someone offers only waffles, one would take it. But if offered waffles or chocolate, one would take the chocolate. The opportunity cost of eating waffles is sacrificing the chance to eat chocolate. Because the cost of not eating the chocolate is higher than the benefits of eating the waffles, it makes no sense to choose waffles. Of course, if one chooses chocolate, they are still faced with the opportunity cost of giving up having waffles. But one is willing to do that because the waffle’s opportunity cost is lower than the benefits of the chocolate. Opportunity costs are unavoidable constraints on behaviour because one has to decide what’s best and give up the next-best alternative.
- Price Theory
Price theory is a field of economics that uses the supply and demand framework to explain and predict human behavior. It is associated with the Chicago School of Economics. Price theory studies competitive equilibrium in markets to yield testable hypotheses that can be rejected.
Price theory is not the same as microeconomics. Strategic behavior, such as the interactions among sellers in a market where they are few, is a significant part of microeconomics but is not emphasized in price theory. Price theorists focus on competition believing it to be a reasonable description of most markets that leaves room to study additional aspects of tastes and technology. As a result, price theory tends to use less game theory than microeconomics does.
Price theory focuses on how agents respond to prices, but its framework can be applied to a wide variety of socioeconomic issues that might not seem to involve prices at first glance. Price theorists have influenced several other fields including developing public choice theory and law and economics. Price theory has been applied to issues previously thought of as outside the purview of economics such as criminal justice, marriage, and addiction.