Technological Change and Demand for Redistribution
Latest draft: September 30, 2026
Job Market Paper
Abstract: I study how technological change drives rising income inequality and non-increasing tax progressivity from 1978 to 2018. Linking occupational data with individual survey responses on preferences for income redistribution, I document that workers in computer-intensive occupations support redistribution less and that changes in preferences for redistribution closely track changes in earnings and employment. Motivated by these findings, I develop and estimate a quantitative model embedding sorting over occupations, the adoption of computer equipment, and voting over redistribution in response to technological change. Changes in worker productivity across demographics, occupations, and types of equipment account for most of the model-implied decline in progressivity and the rise in inequality. Preferred progressivity falls most where workers gain most from sorting into computer-equipped occupations and therefore lose most from progressive taxation. Unequal political weights modestly reinforce the total decline but more than double the part that technological change accounts for.
Dynamics of U.S. Tax Progressivity: A Quantile Approach (with Wentao Hu, Kun Ho Kim, Wei Biao Wu)
Latest draft: June 2, 2025 (new draft in preparation)
Abstract: This paper investigates the dynamics of U.S. tax progressivity from 1978 to 2022 by conducting year-by-year quantile regression and simultaneous inference on progressivity estimates. We find that: (i) the least-squares fit of the widely used log-linear tax function capturing the residual income elasticity worsens during recessions, (ii) the U.S. progressivity is counter-cyclical at all income quantiles, with stronger counter-cyclicality at higher income quantiles; (iii) the constancy of the progressivity is rejected in the 1980s with a gradual decline and during recessions with jumps in the progressivity. During recessions, least-squares-implied tax rate is unusually higher than those from the quantile approach.
The Political Economy of Government Mortgage Guarantees (with Dong Ho Kang)
Latest draft: October 29, 2026
Abstract: Government guarantee of mortgage credit risk has survived decades of reform, even though normative analyses find that it lowers aggregate welfare. To understand why the policy that is realized diverges from the policy that is optimal, we develop a quantitative housing model in which the guarantee fee is selected by a political criterion. The economy is populated by groups with opposing stakes in mortgage policy and different degrees of patience: impatient borrowers, who finance housing with defaultable long-term mortgages and choose between owning and renting, and patient savers, who own the rental sector. Raising the fee is passed through to the mortgage rate, lowers house prices and the housing stock, and redistributes permanently from borrowers to savers. Whether the fee is raised therefore depends on the horizon over which each group's stake is capitalized. A planner who values claims over an infinite horizon adopts a fee of about 130 basis points, just below the level at which the guaranteed channel disappears, whereas a policymaker accountable over any empirically relevant horizon retains the low fee. No fee increase is politically adopted at horizons shorter than roughly 52 years, an order of magnitude longer than an electoral term. The guarantee persists not because it is optimal, but because those who would lose from its removal are impatient and hold a large stake over empirically relevant political horizon.
The Expansion of Social Media Platforms through Intangible Investment (with Xiaohan Zhang)
Latest draft: December 24, 2025
Abstract: Social media platforms have expanded rapidly since the early 2000s as households shifted time toward online leisure, despite modest growth in measured labor and physical capital. To understand this gap, we build a multi-sector dynamic general equilibrium model in which platforms use online traffic and invest in intangibles, including leisure-enhancing technologies and data-intensive capital. Calibrating the model to time-use data, firm financial statements, and website traffic, we infer intangible values and productivity paths. From 2003 to 2023, platform growth is driven mainly by intangible accumulation and platform productivity, with intangible investment rising from 0.11% to 3.27% of GDP.
Endogenous Voter Turnout and the Dynamics of Social Security in General Equilibrium
Latest draft: March 31, 2026
Abstract: This paper studies how endogenous voter turnout shapes intergenerational redistribution and capital accumulation in a dynamic political economy model. I embed turnout in an overlapping generations framework with repeated voting over pay-as-you-go Social Security policy. Endogenous turnout opens two strategic channels absent under exogenous turnout: a static channel through which participation affects contemporaneous political weights, and a dynamic channel through which current policy alters future capital, political weights, and policy. Analyzing transition dynamics in response to U.S. demographic projections under alternative political regimes, I find that mandatory voting eliminates turnout asymmetries but amplifies taxes and lowers long-run capital and welfare.
Evidence of Limited Correspondence between Environmental Social and Governance Scores and Future Corporate Carbon Damages (with Yeong Jae Kim, Sehoon Kim, Moonyoung Kim, Ju Hyun Pyun)
Latest draft: July 15, 2026 (Draft not publicly available due to journal requirement)
Abstract: Environmental, Social, and Governance scores are widely used to evaluate corporate sustainability. While ESG assessments are generally based on process-based indicators rather than direct measures of environmental impacts, it remains unclear whether they correspond to firms’ projected climate damages. We address this question by applying firm-level carbon burden, the discounted value of projected climate damages, in South Korea, where carbon-intensive industries and comprehensive firm-level emissions disclosure provide an informative setting. Using forecasted firm-level emissions and updated social cost of carbon estimates from the U.S. Environmental Protection Agency, we derive firms’ carbon burdens. We find that firms with higher ESG scores tend to have higher carbon burdens, with the positive association strongest among low-GHG emitting firms. These findings suggest that incorporating forward-looking outcome-based measures such as carbon burden could strengthen climate-related transparency and sustainability evaluations.
Selected Works in Progress
Skill-promoting Policy and Changes in Technology and Labor Market Power (with Han Gao)
Online Leisure and Digital Platforms in an Open Economy (with Xiaohan Zhang)
Firm-Establishment Matched Greenhouse Gas Emissions Data in South Korea from 2011 to 2023 (with Yeong Jae Kim, Sehoon Kim, Moonyoung Kim, Ju Hyun Pyun)
Discussion Slides
Discussion Slides for “Perceived versus Calibrated Income Risks in Heterogeneous-agent Consumption Models,” by Tao Wang
Discussion Slides for “Unmasking Social Security: Navigating the Impact on Welfare Distribution,” by Eungsik Kim
Discussion Slides for “Does Protectionism Save Domestic Jobs?: New Evidence from Tariffs on Washing Machines,” by Jaerim Choi