To understand how best to combat COVID-19, we must understand how deadly is the disease. There is a substantial debate in the epidemiological lit- erature as to whether the fatality rate is 1% or 0.1% or somewhere in between. In this note, I use an SIR model to examine why it is difficult to...

This note is intended to introduce economists to a simple SIR model of the progression of COVID-19 in the United States over the next 12-18 months. An SIR model is a Markov model of the spread of an epidemic in a population in which the total population is divided into categories of being...

I present a behavioral epidemiological model of the evolution of the COVID epidemic in the United States and the United Kingdom over the past 12 months. The model includes the introduction of a new, more contagious variant in the UK in early fall and the US in mid December. The model is...

I use a model of private and public behavior to mitigate disease transmission during the COVID pandemic over the past year in the United States to address two questions: What dynamics of infections and deaths should we expect to see from a pandemic? What are our options for mitigating the impact...

The CDC reports that 1.13 million Americans have died of COVID-19 through June of 2023. I use a model of the impact over the past three years of vaccines and private and public behavior to mitigate disease transmission during the COVID-19 pandemic in the United States to address two questions....

This paper analyses the effects of open market operations on interest rates in a model in which agents must pay a fixed cost to exchange assets and cash. Asset markets are endogenously segmented in that some agents choose to pay the fixed cost and some do not. When the fixed cost is zero, the...

The US net foreign asset position has deteriorated sharply in the years following the Global Financial Crisis and is currently negative 65 percent of US GDP. This deterioration primarily reflects changes in the relative values of large gross international equity positions, as opposed to net new...

What quantitative lessons can we learn from models of endogenous technical change through innovative investments by firms for the impact of changes in the economic environment on the dynamics of aggregate productivity in the short, medium, and long run? We present a unifying model that nests a...

We document four facts about the COVID-19 pandemic worldwide relevant for those studying the impact of non-pharmaceutical interventions (NPIs) on COVID-19 transmission. First: across all countries and U.S. states that we study, the growth rates of daily deaths from COVID-19 fell from a wide...

We use a simple random growth model to study the role of changing dynamics of family firms in shaping the evolution of top wealth shares in the United States over the course of the past century. Our model generates a time path for top wealth shares remarkably similar to those found by Saez and...