This paper argues that in the presence of intersectoral input-output linkages, microeconomic idiosyncratic shocks may lead to aggregate fluctuations. In particular, it shows that, as the economy becomes more disaggregated, the rate at which aggregate volatility decays is determined by the...

We study optimal monetary policy in an environment in which firms' pricing and production decisions are subject to informational frictions. Our framework accommodates multiple formalizations of these frictions, including dispersed private information, sticky information, and certain forms of...

We study competition among a score of firms participating in an online market for a commodity-type memory module. Firms were able to adjust prices continuously; prices determined how the firms were ranked and listed (lowest price listed first), with better ranks contributing to firms' sales....

The conventional wisdom is that politicians' rent seeking motives increase public debt and deficit. This is because myopic politicians face political risk and prefer to extract political rents as early as possible. An implication of this argument is that governments will under-save during a...

This paper revisits and critically reevaluates the widely-accepted modernization hypothesis which claims that per capita income causes the creation and the consolidation of democracy. We argue that existing studies and support for this hypothesis because they fail to control for the presence of...

We develop results for the use of LASSO and Post-LASSO methods to form first-stage predictions and estimate optimal instruments in linear instrumental variables (IV) models with many instruments, p, that apply even when p is much larger than the sample size, n. We rigorously develop asymptotic...

In this paper we study post-model selection estimators which apply ordinary least squares (ols) to the model selected by first-step penalized estimators, typically lasso. It is well known that lasso can estimate the non-parametric regression function at nearly the oracle rate, and is thus hard...

We propose a pivotal method for estimating high-dimensional sparse linear regression models, where the overall number of regressors p is large, possibly much larger than n, but only s regressors are significant. The method is a modification of the lasso, called the square-root lasso. The method...

Iron deficiency anemia is frequent among the poor worldwide. While it can be prevented with the appropriate supplement or food fortification, these programs often do not consistently reach the poorest. This paper reports on the impact of a potential strategy to address iron deficiency anemia in...

This paper argues that there was enough buying and selling (emptio venditio) in the early Roman Empire to show that there were markets, and there were enough markets at the time that there was a market economy. I use three examples to make these points, one from my research, one from the...