Research


Above: Petra, Jordan, 2012.



Working Papers:


"Changing income risk across the US skill distribution: Evidence from a generalized Kalman filter," Joint with J. Carter Braxton, Jonathan Rothbaum, and Lawrence Schmidt (First draft: July 2021)

Abstract:  For whom has earnings risk changed and why? To answer these questions, we develop a filtering method which estimates parameters of an income process and recovers persistent and temporary earnings for every individual at every point in time. Our estimation flexibly allows for first and second moments of shocks to depend upon observables as well as spells of zero earnings (i.e. unemployment) and easily integrates into theoretical models. We apply our filter to a unique linkage of 23.5m SSA-CPS records. We first demonstrate that our earnings-based filter successfully captures observable shocks in the SSA-CPS data such as job switching and layoffs. We then show that despite a decline in overall earnings risk since the 1980s, persistent earnings risk has risen for both employed and unemployed workers, while temporary earnings risk declined. Furthermore, the size of persistent earnings losses associated with full year unemployment has increased by 50%. Using geography, education, and occupation information in the SSA-CPS records, we refute hypotheses related to declining employment and wages among routine workers, declining employment prospects for low-skill workers, as well as geographically concentrated increases in risk around the Rust-Belt. Instead, we provide evidence that the rise in persistent earnings risk is a high skill worker phenomenon.  Lastly, we find that rising persistent earnings risk while employed (unemployed) leads to welfare losses equivalent to 1.8% (0.7%) of lifetime consumption, and larger persistent earnings losses while unemployed leads to a 3.3% welfare loss.


"Can the Unemployed Borrow? Implications for Public Insurance," Joint with J. Carter Braxton, and Gordon Phillips. (R&R Journal of Political Economy)

Abstract:  We show that unemployed individuals maintain significant access to credit. Following job loss, the unconstrained borrow, while the constrained default and delever. Both defaulters and borrowers are using credit to smooth consumption. We quantitatively show that long-term credit relationships and credit-registries allow the unemployed to partially offset income losses using credit. We estimate the model and find that the optimal provision of public insurance is unambiguously lower with greater credit access. Using a utilitarian welfare criterion, the optimal steady-state policy is to lower the replacement rate of public insurance from the current US policy of 41.2% to 38.3%. Moreover, lowering the replacement rate to 38.3% yields welfare gains to the majority of workers along the transition path.


"Production and Learning in Teams,Joint with Jeremy Lise, Guido Menzio, and Gordon Phillips. (R&R Econometrica)
[NBER Working Paper No. 25179 , MediumWCEG, WSJ (blog), Bloomberg] (First draft: June 2017, previously titled "Knowledge Diffusion in the Workplace""Knowledge Diffusion Within and Across Firms" and "Worker Mobility and the Diffusion of Knowledge") 

Abstract:  The effect of coworkers on the learning and the productivity of an individual is measured combining theory and data. The theory is a frictional equilibrium model of the labor market in which production and the accumulation of human capital of an individual are allowed to depend on the human capital of coworkers. The data is a matched employer-employee dataset of US firms and workers. The measured production function is supermodular. The measured human capital function is non-linear: Workers catch-up to more knowledgeable coworkers, but are not dragged-down by less knowledgeable ones. The market equilibrium features a pattern of sorting of coworkers across teams that is inefficiently positive. This inefficiency results in low human capital individuals having too few chances to learn from more knowledgeable coworkers and, in turn, in a stock of human capital and a flow of output that are inefficiently low.


"Labor Market Power", Joint with David Berger and Simon Mongey. (R&R American Economic Review
(First presentation: July 2018, SED) [Marginal RevolutionCenter for American ProgressEconfip]

Abstract: To measure labor market power in the US economy, we develop a tractable quantitative, general equilibrium, oligopsony model of the labor market. We estimate key model parameters by matching the firm-level relationship between labor market share and employment size and wage responses to state corporate tax changes. The model quantitatively replicates quasi-experimental evidence on (i) imperfect productivity-wage pass-through, (ii) strategic behavior of dominant employers, and (iii) the local labor market impact of mergers. We then measure welfare losses relative to the efficient allocation. Accounting for transition dynamics, we quantify welfare losses from labor market power relative to the efficient allocation as roughly 6 percent of lifetime consumption. An analytical decomposition attributes equal parts to dead-weight losses and misallocation. Lastly, we find that declining local concentration added 4 ppt to labor's share of income between 1977 and 2013.


"How Credit Constraints Impact Job Finding Rates, Sorting & Aggregate Output," Joint with Gordon Phillips and Ethan Cohen-Cole.  (R&R Review of Economic Studies)
(First Draft: March 2015) 

Abstract:  How do consumer credit markets affect the allocation of workers to firms? To answer this question, we integrate risk aversion and borrowing into a model with worker and firm heterogeneity. We use the model to estimate the impact of credit limits on job search behavior, and then we validate our model predictions using a new panel dataset linking consumer credit to individual job outcomes. We then assess the effects of credit expansion between 1964 and 2004 on sorting and welfare. Credit expansions let low human capital workers, who are typically constrained, find more capital intensive jobs. Consequently, sorting declines (`bad' workers get `good' jobs). However, output, productivity and welfare improve.


"Patent Publication and Innovation," Joint with Deepak Hegde and Chenqi Zhu. (R&R Journal of Political Economy)
(First draft: January 2015, previously circulated as "Patent Publication and Technology Spillovers" and "Patent Disclosure" on SSRN [Patent & IP blogBrad Delong's Blog]

Abstract: How does the publication of patents affect innovation? To answer this question, we exploit a large-scale natural experiment — the passage of the American Inventor's Protection Act (AIPA) — that accelerated the public disclosure of most patents in the U.S. by two years. After the passage of AIPA, patents receive more and faster follow-on citations, indicating significant technology diffusion. Technological overlap increases between distant but related patents and decreases between highly similar patents, and patent applications are less likely to be abandoned post-AIPA, suggesting a reduction in duplicative R&D. Firms exposed to longer patent grant delays increased their R&D investment more after AIPA. We estimate AIPA increased patenting by a significant 6.2 percent and increased firms’ R&D investment by up to six percent. These findings are consistent with the predictions of our theoretical framework which models patent publication as provisioning current information about related technologies to inventors.



Abstract: We measure the distribution of welfare losses from non-competitive behavior in the U.S. credit card industry during the 1970s and 1980s.  The early credit card industry was characterized by regional monopolies that excluded competition. Several landmark court cases led the industry to adopt competitive reforms that resulted in greater, but still limited, oligopolistic competition. We measure the distributional consequences of these reforms by developing and estimating a heterogeneous agent, defaultable debt framework with oligopolistic lenders. Welfare gains from greater lender entry in the late 1970s are equivalent to a one-time transfer worth $3,400 (in 2016 dollars) for the bottom decile of earners (roughly 50% of their annual income) versus $900 for the top decile of earners. As the credit market expands, low-income households benefit more since they rely disproportionately on credit to smooth consumption. Lender entry can also account for a significant share of rising defaults, chargeoffs and credit access from the 1970s to 1980s.  Lastly, we find that greater lender entry resulting from these reforms delivers 65% of the potential gains from competitive pricing.


"Informal Unemployment Insurance and Labor Market Dynamics,"  Federal Reserve Bank of St. Louis Working Paper 2012-057, First Draft: December, 2011. [Uses Equifax Data, Includes Partial Default Evidence and Theory]

Abstract:  How do job losers use default --- a phenomenon 6X more prevalent than bankruptcy --- as a type of ``informal'' unemployment insurance, and more importantly, what are the social costs and benefits of this behavior? To this end, I establish several new facts: (i) job loss is the main reason for default, not negative equity (ii) people default because they are credit constrained and cannot borrow more, and (iii) the value of debt payments is a significant fraction of a defaulter's earnings. Using these facts, I calibrate a general equilibrium model with a frictional labor market similar to Menzio and Shi (2009, 2011) and individually priced debt along the lines of Eaton and Gersovitz (1981) and Chatterjee et al. (2007). After proving the existence of a Block Recursive Equilibrium, I find that the extra self-insurance job losers obtain by defaulting outweighs the subsequent increase in the cost of credit, and as a result, protectionist policies such as the Mortgage Servicer Settlement of 2012 or the CARD Act of 2009 improve overall welfare by .1%. The side effect of the policies, however, is a .2-.5% higher unemployment rate during recessions that persists throughout the recovery.



In progress:

"Minimum wages and welfare,"  joint with David Berger and Simon Mongey, First Draft: July, 2021. 

Abstract:  What is the optimal minimum wage? We provide a novel characterization of oligopsonistic labor markets under minimum wages with worker and firm heterogeneity. We then characterize how a macroeconomy with many such markets aggregates to yield two `wedges' implied by minimum wages. The first is an aggregate shadow markdown, that narrows with minimum wage hikes, then tightens as many firms ration employment. The second reflects misallocation, which improves for small values of the minimum wage but steeply worsens at higher values. In our quantitative model, which features worker heterogeneity and replicates recent empirical papers in the minimum wage literature, these effects yield a hump-shaped profile of welfare with respect to the minimum wage.




Publications:

"Testing and Reopening in an SEIR Model" joint with David Berger, Chengdai Huang, and Simon Mongey. (accepted, Review of Economic Dynamics)

Abstract: We quantify how testing and targeted quarantine make it possible to reopen an economy in such a way that output increases while deaths are reduced. We augment a standard Susceptible-Exposed-Infectious-Recovered (SEIR) model with (i) virological testing, (ii) serological testing, (iii) permanently asymptomatic individuals, (iv) incomplete information, and (v) a reduced form behavioral response of reopening to changes in health risks. Virological testing allows for targeted quarantine of asymptotic spreaders. Serological testing allows for targeted release of recovered individuals. We fit our model to U.S. data. Virological tests every two weeks accommodate more aggressive reopening that more than halves output losses while keeping deaths below forecasts under the status quo. Serological tests are much less effective. Implementing testing against a fixed budget, low sensitivity tests that are cheap and used frequently, dominate perfect tests that are expensive and used less frequently.


"The Impact of Consumer Credit Access on Self-Employment and Entrepreneurship," Joint with Gordon Phillips and Ethan Cohen-Cole. (accepted, Journal of Financial Economics) 

Abstract:  We examine how consumer credit affects entrepreneurship by linking three million earnings and pass-through tax records to credit reports.  In the cross-section, we show that self-employment without employees and employer firm ownership increase monotonically with credit limits and credit scores.  We then isolate individuals who have had discrete increases in credit limits after the exogenous removal of bankruptcy flags to measure the effects of personal credit on entrepreneurship. Following bankruptcy flag removal, individuals are more likely to start a new employer business and borrow extensively. Those who own businesses with employees borrow $40,000 more after bankruptcy flag removal, a 33% gain relative to the sample average.   

"The Impact of Consumer Credit Access on Unemployment," Job Market Paper, 2017 revision. (Review of Economic Studies, vol 86(6), pages 2605-2642, 2019[NBER working paper No. 25187, CardRate]
(First Draft: February 2013.  [Online Appendix]) [Codes and data]

Awarded UCLA Welton Prize, Best Paper in Macroeconomics, 2013-2014
  
Abstract:   Unemployed households' access to unsecured revolving credit more than tripled over the last three decades. This paper analyzes how both cyclical fluctuations and trend increases in credit access impact the business cycle. The main quantitative result is that credit expansions and contractions have contributed to moderately deeper and more protracted recessions over the last 40 years.  As more individuals obtained credit from 1977 to 2010, cyclical credit fluctuations affected a larger share of the population and became more important determinants of employment dynamics.  Even though business cycles are more volatile, newborns strictly prefer to live in the economy with growing, but fluctuating, access to credit markets.

Notes: Previously titled and circulated as "The Supply Side of Jobless Recoveries"  

"The Impact of Foreclosure Delay on U.S. Employment," with Lee E. Ohanian.  NBER Working Paper No. 21532, 2015. (Review of Economic Dynamics, Volume 31, January 2019, Pages 63-83)
(Retitled and previously circulated as "Foreclosure delay and US unemployment" Federal Reserve Bank of St. Louis Working Paper 2012-017A, First Draft: December, 2011.) [Washington Center for Equitable GrowthEconTalk, Minneapolis Fed[Codes and data]

Abstract:  This paper documents that the time required to initiate and complete a home foreclosure rose from about 9 months on average prior to the Great Recession to an average of 15 months during the Great Recession and afterward. We refer to these changes as foreclosure delay. We also document that many borrowers who are in foreclosure ultimately exit foreclosure and keep their homes by making up for missed mortgage payments. We analyze the impact of foreclosure delay on the U.S. labor market as an implicit credit line from a lender to a borrower (mortgagor) within a search model. In the model, foreclosure delay provides unemployed mortgagors with additional time to search for a high-paying job. We find that foreclosure delay decreases mortgagor employment by about 0.75 percentage points, nearly doubles the stock of delinquent mortgages, increases the rate of homeownership by about 0.3 percentage points, and increases job match quality, as mortgagors search longer. Severe foreclosure delays, such as those observed in Florida and New Jersey, can depress mortgagor employment by up to 1.3 percentage points. The model results are consistent with PSID and SCF data that show that employment rates rise for delinquent mortgagors once the mortgagor is in the foreclosure process.

"Can't Pay or Won't Pay? Unemployment, Negative Equity, and Strategic Default,” with Kris Gerardi, Lee E. Ohanian, and Paul Willen,  NBER Working Paper No. 21630, 2015. (Published in The Review of Financial Studies, Volume 31, Issue 3, March 2018)
 (Retitled and Previously Circulated as Atlanta Fed Working Paper "Unemployment, negative equity, and strategic default" and Ziman Center Working Paper "What Actually Causes, Defaults, Redefaults, and Modifications." First Draft: February, 2012).  [VoxEUUrban InstituteCalculated Risk , AroundTheFedJournalistResource

Additional Files: Online Appendix, and Replication Files: [Codes and Data] [Weights: PSID-CRISM mortgage weights.doPSID-CRISM mortgage weights.dta]

Abstract: This paper uses new data from the PSID to quantify the relative importance of negative equity versus ability to pay, in driving mortgage defaults between 2009 and 2013. These data allow us to construct household budgets sets that provide better measures of ability to pay. Changes in ability to pay have large estimated effects. Job loss has an equivalent effect on the propensity to default as a 35 percent decline in equity. Strategic motives are also found to be quantitatively important, as we estimate more than 38 percent of households in default could make their mortgage payments without reducing consumption.

"Tarnishing the Golden and Empire States: Land-Use Regulations and the U.S. Economic Slowdown," Joint with Lee E. Ohanian and Edward C. Prescott (Published in the Journal of Monetary Economics, Volume 93, January 2018)

Abstract:  This paper studies the impact of state-level land-use restrictions on U.S. economic activity, focusing on how these restrictions have depressed macroeconomic activity since 2000. We use a variety of state-level data sources, together with a general equilibrium spatial model of the United States to systematically construct a panel dataset of state-level land-use restrictions between 1950 and 2014. We show that these restrictions have generally tightened over time, particularly in California and New York. We use the model to analyze how these restrictions affect economic activity and the allocation of workers and capital across states. Counterfactual experiments show that deregulating existing urban land from 2014 regulation levels back to 1980 levels would have increased US GDP and productivity roughly to their current trend levels. California, New York, and the Mid-Atlantic region expand the most in these counterfactuals, drawing population out of the South and the Rustbelt. General equilibrium effects, particularly the reallocation of capital across states, account for much of these gains.

"Labor Market Dysfunction During the Great Recession," with Lee E. Ohanian. Cato Papers on Public Policy, edited by Jeffrey Miron, Volume 1, 2011.[ Wall Street Journal Article, Economist Recommendation



Abstract: This paper documents the abnormally slow recovery in the labor market during the Great Recession, and analyzes how mortgage modification policies contributed to delayed recovery. By making modifications means-tested by reducing mortgage payments based on a borrower's current income, these programs change the incentive for households to relocate from a relatively poor labor market to a better labor market. We .find that modifications raise the unemployment rate by about 0.5 percentage points, and reduce output by about 1 percent, reflecting both lower employment and lower productivity, which is the result of individuals losing skills as unemployment duration is longer.

Why the U.S. Economy Has Failed to Recover and What Policies Will Promote Growth,” with Lee E. Ohanian, Government Policies and the Delayed Economic Recovery, edited by Lee E. Ohanian, John B. Taylor, and Ian Wright, 2012.

Abstract: This study examines the recovery from the 2008-2009 recession from the perspective of the neoclassical growth model, thus extending Ohanian's (2010) neoclassical analysis of the downturn phase of this recession. This paper documents the characteristics and features of the recovery, identifies the sources of economic weakness, discusses the possible impact of economic policies on the recovery, and provides an assessment of what types of policies may help accelerate the speed of the recovery and restore prosperity.




Discussion slides:

Discussion Slides for ``Granular Search, Market Structure, and Wages'' by Gregor Jarosch, Jan Nimczik, Isaac Sorkin

Discussion Slides for ``The Cyclicality of Hiring and Separations'' by Alice Nakamura, Emi Nakamura, Kyle Phong, and Jon Steinsson

Discussion Slides for ``Time Consistent Fiscal Policy in a Debt Crisis'' by Neele Balke and Morten Ravn

Discussion Slides for ``Bad Credit, No Problem? Credit and Labor Market Consequences of Bad Credit Reports" by Dobbie, Goldsmith-Pinkham, Mahoney, Song.

Discussion Slides for ``The Effect of Debt on Consumption and Delinquency: Evidence from Housing Policy in the Great Recession'' by Peter Ganong and Pascal Noel.

Discussion Slides for ``Aggregate Recruiting Intensity'' by Alessandro Gavazza, Simon Mongey, Giovanni L. Violante.

Discussion Slides for ``Business Cycles and Household Formation'' by Sebastian Dyrda, Greg Kaplan, Jose-Victor Rios-Rull.