This chapter surveys the recent literature on the theory of macroeconomic policy. We study the effect of various incentive constraints on the policy making process, such as lack of credibility, political opportunism, political ideology, and divided government. The survey is organized in three...

In this paper we study the evolution of central banks' balance sheets in 12 advanced economies since 1900. We find that balance sheet size in most developed countries has fluctuated within rather clearly defined bands relative to output. Historically, clusters of big expansions and contractions...