My research is at the intersection of spatial economics, international trade, and development economics. It aims to evaluate how large-scale policy changes affect overall welfare and equity in economic opportunities. I apply trade and microeconomic theories and employ data from countries that have experienced significant legal reforms, such as Vietnam.
Working Papers
Place-based Policy, Migration Barriers, and Spatial Inequality
How should governments reduce spatial inequality: by attracting firms to disadvantaged regions or helping people reach thriving ones? Vietnam implemented both types of policies simultaneously through place-based tax incentives for firms in 2003 and the relaxation of the household registration system (Ho Khau) in 2005. I analyze these policies using a dynamic spatial general equilibrium model with firm life cycles and endogenous public services, and estimate key elasticities from policy-induced variations. The combined policies raise aggregate welfare by 1.3% and reduce spatial inequality by 0.7%. Migration reform alone reduces spatial inequality three times more than tax incentives. However, the migration policy’s impact depends critically on destination targeting: facilitating migration to the largest cities generates minimal redistribution, while reducing barriers to other destinations reduces spatial inequality by 1.3%, nearly double the combined policy effect. These findings suggest that strategic policy design matters more than choosing between firm-based and people-based approaches.
We study how trade liberalization affects sex selection in a son-preferring society. Using the Vietnam–US 2001 trade agreement as a natural experiment, we exploit industry-level tariff cuts in a difference-in-differences framework. We find that women in exposed industries are more likely to have male children, work more, and have fewer births—effects driven solely by maternal, not paternal, exposure. A quantity-quality model with maternal time costs explains these patterns. Our findings reveal that rising maternal opportunity costs, rather than income or relative returns effects, can increase sex selection during economic transitions.
@unpublished{HuynhNguyen:2025,Author = {Nghi\^em Q. Hu\`ynh and Ngoc T. T. Nguyen},Note = {Working paper},Title = {Trade, Maternal Time Costs, and Sex Selection: Evidence from Vietnam},Year = {2025}}