During the Second Industrial Revolution, 1860–1900, many new technologies, including electricity, were invented. These inventions launched a transition to a new economy, a period of about 70 years of ongoing, rapid technical change. After this revolution began, however, several decades passed...

Herd behavior is argued by many to be present in many markets. Existing models of such behavior have been subjected to two apparently devastating critiques. The continuous investment critique is that in the basic model herds disappear if simple zero-one investment decisions are replaced by the...

Here we reply to Robert Solow’s comment (forthcoming) on our work (Chari and Kehoe (2007)).

Bulow and Rogoff (1989b) show that as long as governments can earn the market rate of return by saving abroad, standard reputation models cannot support debt. We argue that these standard reputation models are partial in the sense that actions of agents in one arena affect reputation in that...

In the data, prices change both temporarily and permanently. Standard Calvo models focus on permanent price changes and take one of two shortcuts when confronted with the data: drop temporary changes from the data or leave them in and treat them as permanent. We provide a menu cost model that...

This paper proposes a simple method for guiding researchers in developing quantitative models of economic fluctuations. We show that a large class of models, including models with various frictions, are equivalent to a prototype growth model with time-varying wedges that, at least at face value,...

We analyze the optimal design of monetary rules. We suppose there is an agreed upon social welfare function that depends on the randomly fluctuating state of the economy and that the monetary authority has private information about that state. We suppose the government can constrain the policies...

We evaluate the ability of models with putty-clay capital and stochastic energy prices to account for the dynamics of energy use and output. Economists have noted a close relationship between changes in the price of energy and changes in output. Moreover, they have documents that this...

Time-varying risk is the primary force driving nominal interest rate differentials on currency-denominated bonds. This finding is an immediate implication of the fact that exchange rates are roughly random walks. We show that a general equilibrium monetary model with an endogenous source of risk...