Chapter 22: Frontiers of Microeconomics

The first major topic addresses asymmetric information, a situation where different parties in a transaction possess unequal knowledge about product quality, risk, or relevant circumstances. This information imbalance generates two critical problems: adverse selection occurs when the less-informed party attracts a disproportionate share of high-risk or low-quality participants, exemplified by health insurance markets where individuals with anticipated medical needs are more likely to purchase coverage; moral hazard emerges when one party's behavior changes following a transaction, such as when insured drivers take greater risks knowing losses are covered. The chapter distinguishes between signaling, where informed parties voluntarily reveal information through costly actions like obtaining educational credentials to demonstrate competence, and screening, where uninformed parties design contractual mechanisms or testing procedures to extract hidden information from those with private knowledge. The discussion then shifts to political economy and collective decision-making, introducing foundational results about voting and preference aggregation. The Condorcet paradox illustrates how individual preferences that appear rational can produce inconsistent collective rankings through majority voting. Arrow's impossibility theorem formally establishes that no voting procedure can simultaneously satisfy reasonable fairness criteria and convert individual preferences into a consistent social ordering. The median voter theorem explains why democratic systems with majority-rule voting tend toward policy positions favored by the median voter, accounting for observed political convergence. Public choice theory examines how interest groups, lobbying activities, and bureaucratic self-interest shape policy outcomes in ways that often diverge from efficiency or broad public welfare. Finally, the chapter incorporates behavioral economics, which recognizes that actual human decision-making deviates systematically from the rationality assumption underlying traditional models. Key behavioral concepts include bounded rationality, where cognitive limits constrain decision quality; loss aversion, the tendency to weight losses more heavily than equivalent gains; and preference for fairness, which motivates economically irrational choices. These insights explain real-world phenomena such as insufficient retirement savings, susceptibility to irrelevant anchoring effects, and willingness to sacrifice material benefit to punish unfairness.