This paper examines the econometric causal model for policy analysis developed by the seminal ideas of Ragnar Frisch and Trygve Haavelmo. We compare the econometric causal model with two popular causal frameworks: Neyman-Holland causal model and the do-calculus. The Neyman-Holland causal model...

This paper uses the concept of the triad census first introduced by Holland and Leinhardt, and describes several distributions on directed graphs. Methods are presented for calculating the mean and the covariance matrix of the triad census for the uniform distribution that conditions on the...

We define a general class of network formation models, Statistical Exponential Random Graph Models (SERGMs), that nest standard exponential random graph models (ERGMs) as a special case. We provide the first general results on when these models' (including ERGMs) parameters estimated from the...

Haavelmo's seminal 1943 paper is the first rigorous treatment of causality. In it, he distinguished the definition of causal parameters from their identification. He showed that causal parameters are defined using hypothetical models that assign variation to some of the inputs determining...

We propose an easy-to-use search friction in the goods markets in medium-sized New Keynesian models. This friction allows increases in measured productivity in response to increases in expenditures via higher search effort from households. As a result markups can become procyclical and labor...

As search frictions become smaller in the market for a consumer product, buyers are able to locate and access more sellers per unit of time. In response, sellers choose to design varieties of the product that are more specialized in order to exploit differences in the buyers' preferences. I find...

We explore the impact of wage offers on job applications, testing implications of the directed search model and trying to distinguish it from random search. We use a field experiment conducted on a Chinese job board, with real jobs for which we randomly varied the wage offers across three...

We study a model of retrospective search in which an agent--a researcher, an online shopper, or a politician--tracks the value of a product. Discoveries beget discoveries and their observations are correlated over time, which we model using a Brownian motion. The agent, a standard exponential...

We study a model of collective search by teams. Discoveries beget discoveries and correlated search results are governed by a Brownian path. Search results' variation at any point---the search scope---is jointly controlled. Agents individually choose when to cease search and implement their best...

I study a search equilibrium model of the labor market in which workers have stubborn beliefs about their labor market prospects, i.e. beliefs about their probability of finding a job and the wage they will earn that do not respond to aggregate fluctuations in fundamentals. I show that, when...