When labor is indivisible, there exist efficient outcomes with some agents randomly unemployed, as in Rogerson (1988). We integrate this idea into the modern theory of monetary exchange, where some trade occurs in centralized markets and some in decentralized markets, as in Lagos and Wright (2005). This delivers a general equilibrium model of unemployment and money, with explicit microeconomic foundations. We show that the implied relation between inflation and unemployment can be positive or negative, depending on simple preference conditions. Our Phillips curve provides a long-run, exploitable, trade-off for monetary policy; it turns out, however, that the optimal policy is the Friedman rule.

Peter A. Diamond discusses search equilibrium as a framework for integrating micro and macroeconomics.

To study the determination of the natural rate path, Phelps constructs three stylized general-equilibrium models, each one built around a distinct kind of asset in which firms invest and which is important for the hiring decision.

This book is concerned with the problem of wage rigidities in macroeconomic theory, and their implications for public policy. It offers an analysis of the microeconomic foundations of rigid wages, considering their implications for normative economics, and their role in explaining involuntary unemployment. The initial chapters examine short-run macroeconomic equilibrium with nominal rigidities within the framework of fix-price temporary equilibria. This is followed by an overview and assessment of the main microeconomic mechanisms likely to account for real wage rigidity. In this context new findings concerning implicit contract theory, union behaviour and efficiency wage models are reported. The effect of efficiency wage models on macroeconomic fluctuations is also considered. Finally an analysis of the important public policy issues raised in the book is provided.