Standard measures of productivity display enormous dispersion across farms in Africa. Crop yields and input intensities appear to vary greatly, seemingly in conflict with a model of efficient allocation across farms. In this paper, we present a theoretical framework for distinguishing between...

We examine the economic impact of high-yielding crop varieties (HYVs) in developing countries 1960-2000. We use time variation in the development and diffusion of HYVs of 10 major crops, spatial variation in agro-climatically suitability for growing them, and a differences-in-differences...

We update Rose and Spiegel (2009a, b) and search for simple quantitative models of macroeconomic and financial indicators of the "Great Recession" of 2008-09. We use a cross-country approach and examine a number of potential causes that have been found to be successful indicators of crisis...

In our European Economic Review (2002) paper, we used pre-1998 data on countries participating in and leaving currency unions to estimate the effect of currency unions on trade using (then-) conventional gravity models. In this paper, we use a variety of empirical gravity models to estimate the...

An empirical model of time-varying realignment risk in an exchange rate target zone is developed. Expected rates of devaluation are estimated as the difference between interest race differentials and estimated expected rates of depreciation within the exchange rate band, using French...

Realignment expectations which measure exchange rate credibility are analyzed for European exchange rates, using daily financial data since the inception of the EMS. It is difficult to find economically meaningful relationships between realignment expectations and macroeconomic variables,...

This paper presents an empirical analysis of speculative attacks on pegged exchange rates in 22 countries between 1967 and 1992. We define speculative attacks or crises as large movements in exchange rates, interest rates, and international reserves. We develop stylized facts concerning the...