Small-area-variation studies have shown that physician treatment styles differ substantially both between and within markets, controlling for patient characteristics. Using a data set containing the universe of deliveries in Florida over a 12-year period with consistent physician identifiers and...

We study the properties of generalized stochastic gradient (GSG) learning in forward-looking models. We examine how the conditions for stability of standard stochastic gradient (SG) learning both differ from and are related to E-stability, which governs stability under least squares learning. SG...

This paper studies the effect of interest rates on investment in an environment where firms make irreversible investments and learn over time. In this setting, changes in the interest rate affect both the cost of capital and the cost of delaying investment. These two forces combine to generate...

Using data on stock purchases individual investors made through a discount broker from 1991 to 1996, we study information diffusion effects the relation between household investment choices and those made by their neighbors. A ten percentage point increase in neighbors' purchases of stocks from...

This paper proposes a theory of liquidity dynamics. Illiquidity results from asymmetric information. Observing the historical track record teaches agents how to interpret public information and helps overcome information asymmetry. There can be an illiquidity trap: too much asymmetric...

Many economists believe knowledge production generates positive spillovers among knowledge producers. The available evidence, however, is mixed. We argue that spillovers can exist along three dimensions (idea, geographic, and collaboration space). To isolate the key channel through which...