Microeconomics
Channel: 宇宙のすべての知識 プリンシピア
Date: 2019-01-04

Microeconomics, by Wikipedia https://en.wikipedia.org/wiki?curid=18819 / CC BY SA 3.0

Microeconomics

Microeconomics (from Greek prefix "mikro-" meaning "small" + "economics") is a branch of economics that studies the behaviour of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms.

One goal of microeconomics is to analyze the market mechanisms that establish relative prices among goods and services and allocate limited resources among alternative uses. Microeconomics shows conditions under which free markets lead to desirable allocations. It also analyzes market failure, where markets fail to produce efficient results.

Microeconomics stands in contrast to macroeconomics, which involves "the sum total of economic activity, dealing with the issues of growth, inflation, and unemployment and with national policies relating to these issues". Microeconomics also deals with the effects of economic policies (such as changing taxation levels) on the aforementioned aspects of the economy. Particularly in the wake of the Lucas critique, much of modern macroeconomic theory has been built upon microfoundations—i.e. based upon basic assumptions about micro-level behavior.

Microeconomic theory typically begins with the study of a single rational and utility maximizing individual. To economists, rationality means an individual possesses stable preferences that are both complete and transitive. 

The technical assumption that preference relations are continuous is needed to ensure the existence of a utility function. Although microeconomic theory can continue without this assumption, it would make comparative statics impossible since there is no guarantee that the resulting utility function would be differentiable.

Microeconomic theory progresses by defining a competitive budget set which is a subset of the consumption set. It is at this point that economists make The technical assumption...