Research

Contagion at Work: Occupations, Industries, and Human Contact, 2021 (with Anna Houstecka and Raul Santaeulalia-Llopis) [paper]
Journal of Public Economics, Volume 200, pp.1-20.

Abstract: Using nationally representative micro panel data on flu incidence from the Medical Expenditure Panel Survey in the United States, we show that employed individuals are on average 35.3% more likely to be infected with the flu virus. Our results are robust to individual characteristics including vaccinations, health insurance, and individual fixed effects. Within the employed, we find significant differences in flu incidence by occupation (e.g., sales occupations show 40.5% higher probability of infection than farmers) and by industry (e.g., education, health, and social services show 52.2% higher probability of infection than mining). Further, we show that the interaction between occupations and industries is important to understand contagion. Indeed, cross-industry differences in flu incidence cannot be fully explained by differences in the within-industry occupation structure. As a potential mechanism for contagion, we study how flu incidence varies with the extent of human contact interaction at work—with an occupation-industry-specific score that we construct based on O’NET occupational characteristics. We find that the higher the human contact at work, the greater are the odds of infection. Our results are larger in years of high aggregate flu incidence and robust to firm size, the number of jobs, and hours worked.

Labor Share Decline and Intellectual Property Products Capital, 2020 (with Raul Santaeulalia-Llopis and Yu Zheng) [paper] [online appendix]
Econometrica, Volume 88, Issue 6, pp. 2609-2628

Abstract: We study the behavior of the US labor share over the past 90 years. We find that the observed decline of the labor share is entirely explained by the capitalization of intellectual property products in the national income and product accounts.

Media coverage: World Economic Forum, Washington Center for Equitable Growth, Harvard Law Review Forum

GitHub Repository:
1. IPP_USLS
2. US Labor Share: Quarterly and Annual with IPP Adjustments

Increasing and Decreasing Labor Shares: Cross-Country Differences in the 21st Century, 2019 (with Sangmin Aum and Raul Santaeulalia-Llopis) [paper]
Revistas ICE, No. 911, pp.63-77

Abstract: We study the labor share in the OECD corporate sector for the (early) 21st century. Firstly, the cross-country average is trendless over this medium-run horizon after adjusting for intellectual property products (IPP) rents as in Koh et al. (2017). Secondly, the behavior of the labor share is heterogeneous increasing for equally as many countries (e.g., France and the United Kingdom) as it decreases (e.g., Germany and the United States). Thirdly, the cross-country differences in labor share are driven by the differences in labor productivity growth and not wages.

The Costs of Consumption Smoothing: Less Schooling and Less Nutrition, 2019 (with Leandro M. De Magalhaes and Raul Santaeulalia-Llopis) [paper]
Journal of Demographic Economics, 85(3), pp.181-208

Abstract: Using novel microdata, we explore lifecycle consumption in Sub-Saharan Africa (SSA). We find that households' ability to smooth consumption over the lifecycle is large, particularly, in rural areas. Interestingly, consumption in old age is sustained by shifting to self-farmed staple food, as opposed to traditional savings mechanisms or food gifts. This smoothing strategy entails two important costs. First, there is a loss of human capital as children are diverted away from school and into producing self-farmed food. Second, a diet largely concentrated in staple food (e.g., maize in Malawi) in old age results in a loss of nutritional quality for households headed by the elderly.

Labor Productivity in the Sharing Economy [paper]
Statistics, pp.181-208, November 2018 (in Japanese)
シェアリングエコノミーにおける労働生産性、『統計』、2018年11月号

On the Welfare Cost of Constrained Female Labor Supply, 2024 (with Teng Ma and Logan Miller) [paper]

Abstract: Female labor plays a crucial role as a form of consumption insurance for a household facing income risks. However, utilizing this insurance option comes with its own set of costs and constraints. This study delves into how these constraints impact household welfare through two distinct channels: the insurance channel and the precautionary channel. We empirically and analytically show that these constraints not only hinder consumption smoothing but also intensify the household's precautionary behavior before the shock arrival. Furthermore, our quantitative analysis reveals that eliminating constraints on its extensive margin of female labor mitigates precautionary saving, leading to a whopping 14.6\% boost in welfare. On the other hand, relaxing constraints on the intensive margin of female labor allows for more flexible insurance options, leading to a modest 0.23\% increase in welfare. Just a side note: skipping the wedding bells? That’s a major buzzkill, causing a dismal 11.9\% drop in welfare.

Countercyclical Elasticity of Substitution, 2022 (with Raul Santaeulalia-Llopis) [paper][Appendix]
[Previously circulated under the name "The Shape of the Aggregate Production Function over the Business Cycle and Its implications for the Labor Market"]
Revise and Resubmit at Review of Economic Studies

Abstract: We empirically show that the short-run elasticity of substitution (EOS) between capital and labor is countercyclical. In recessions, capital and labor are more substitutable than in expansions. This countercyclicality of EOS introduces an asymmetry in an otherwise standard competitive-markets business cycle model that contributes to resolving several labor-market puzzles: the labor productivity puzzle, the Dunlop-Tarshis phenomenon, the hours-productivity puzzle, and the labor share puzzle. Interestingly, the cyclicality of EOS is per se not a source of aggregate fluctuations, but it propagates the effects of other shocks.

Working from a Distance: Productivity Dispersion and Labor Reallocation, 2020 (with Jingping Gu and Andrew Liu) [paper][online appendix]

Abstract: Following the shocks of the COVID-19 pandemic, the economy may be significantly changed relative to the pre-pandemic world. One critical shift induced by the COVID-19 pandemic is a need for physical distance (at least 6 feet apart) between workers and customers. In this study, we examine the impacts of social distancing in the workplace on employment and productivity across industries. Using our constructed measure of adaptability to social distancing, we empirically find that industries that are more adaptive to social distancing had less decline in employment and productivity during the pandemic. Using this empirical evidence, our model predicts that employment and productivity dispersion would induce labor reallocation across sectors, while imperfect labor mobility may result in a long road to economic recovery.

HPC-Efficient Parallel Computing in Economics, 2019 [paper]

Abstract: Easier access to high-performance computing (HPC) systems has enabled parallel computing more ubiquitous in numerically solving economic models. For the maximal use of the full capacity of computing power and resources in HPC, it is essential to eliminate parallelization overhead--the additional time required to parallelize a series of tasks to multiple processors. In this study, we demonstrate three parallel computing techniques that effectively reduce the main sources of parallelization overhead in HPC systems.

GitHub Repository: HPC_Parallelization

Growth Facts and Intellectual Property Products Capital, 2018 (with Sangmin Aum and Raul Santaeulalia-Llopis) [paper]

Abstract: We document a rise of intellectual property products (IPP) captured by up-to-date national accounts in 31 OECD countries. These countries gradually adopt the new system of national accounts (SNA08) that capitalizes IPP|which was previously treated as an intermediate expense in the pre-SNA93 accounting framework. We examine how the capitalization of IPP a.ects stylized growth facts and the big ratios (Kaldor, 1957, Jones, 2016). We .nd that the capitalization of IPP generates (a) a decline of the accounting labor share, (b) an increase in the capital-to-output ratio across time, and (c) an increase in the rate of return to capital across time. The key accounting assumption behind the IPP capitalization implemented by national accounts is that the share of IPP rents that are attributed to capital, ., is equal to one. That is, national accounts assume that IPP rents are entirely owed to capital. We question this accounting assumption and apply an alternative split of IPP rents between capital and labor based on the cost structure of R&D as in Koh et al. (2018). We .nd that this alternative split generates a secularly trendless labor share, a constant capital-to-output ratio, and a constant rate of return across time. We discuss the implications of these new measures of IPP capital conditional on .for cross-country income per capita differences using standard development and growth accounting exercises.

Constrained Inefficiency over the Lifecycle

On the Convergence of Simulated Endogenous Grid Methods