Why do couples cohabit before getting married? To answer this, I exploit a survival pension reform in Sweden that imposed eligibility deadline, effectively penalising female partners who married after a cutoff date. The empirical evidence shows that the reform primarily induced long-term cohabiters, those who likely would not have married in the absence of the reform, to marry before the deadline, while newer cohabiters were largely unaffected. To interpret these patterns, I develop a structural life-cycle model in which couples learn about match quality, bargain over their relationship, and choose between cohabitation, marriage, or being single. Early in a relationship, cohabitation complements marriage by allowing couples to gather information about their compatibility before getting married. For long-term cohabiters, however, cohabitation increasingly serves as a substitute, providing many of the same benefits without the formal commitment. The model matches the empirical facts well. I use the model to assess the value of information: couples are willing to give up almost 7% of consumption in each period in order to retain learning. Counterfactual experiments show that de facto marriage laws remove much of the information advantage of cohabitation, leading to earlier but less selective marriages. Joint taxation increases the number of marriages and overall welfare through fiscal transfers, but reduces marital stability.

This paper examines the impact of two family planning policies on demographic change and human capital accumulation in China. Using province-level data on unauthorised births, I build a heterogeneous-agent overlapping generation model to analyse fertility patterns from 1950 to present. The findings reveal that the policies have far-reaching effects beyond birth control and the quantity-quality trade-off. The birth control policy reduces the number of children per family, but with varying impact across socioeconomic groups. Meanwhile, penalties for out-of-quota births disproportionately affect low socioeconomic groups. I further show that the policy-induced rise in overall human capital of children is mainly driven by the composition effect instead of the quantity-quality trade-off. When composition effect dominates, a relaxation in fertility control does not necessarily lower overall human capital. This study reveals that heterogeneous effects can play an important role in shaping human capital and demographics.

Building on prior research about the heterogeneous impact of labor shocks on individuals' propensity to start businesses, we explore how local labor market frictions affect individuals' selection into platform-based entrepreneurship. Combining detailed data from a large online retail platform with sectoral employment statistics across labor market areas in the United States, we show that entrepreneurs entering the platform during larger local employment declines in related sectors developed more effective customer strategies and maintained stronger sales performance. These entrepreneurs focused more on customer appeal, matched social media channels with the platform's predominant user base, and lowered prices over time.

Do losses loom larger than gains in high-stakes, real-world decisionmaking, and does time pressure amplify this effect? We study the behavior of elite competitors in the World Rapid and Blitz Chess Championships, leveraging detailed move-by-move analysis and round-level variation in monetary incentives. Our setting offers a rare natural experiment: participants face substantial, exogenously varying prize incentives and systematically different time constraints, yet compete in an otherwise constant, organizational environment. We find that both prospective gains and prospective losses significantly improve the quality of play, but that loss incentives have a markedly stronger effect. The motivational impact of avoiding a loss is around twice as large as the effect of pursuing an equivalent gain. Crucially, this asymmetry is sharply intensified when chess players operate under greater time pressure.

We documents three facts in marriage (i) At every age women are less likely to remain single than men, especially low-educated women. (ii) Women are more likely to 'marry up', while men more often 'marry down'. iii) As women age, a first marriage is increasingly associated with a penalty: older women marry men of lower socioeconomic status and accept larger age gaps, whereas the same is not observed for men. They disproportionately marry younger women and the marital age gap rises roughly linearly with men’s age. To interpret these facts, we build a tractable equilibrium matching model with age and education heterogeneity, fecundity risk, and within-household bargaining. Individuals face idiosyncratic match values and a declining option value of waiting with age. In equilibrium, a wedge emerges in women’s reservation match quality that grows with female age—the 'single’s stigma'. Calibrated to the moments above, the model reproduces the observed sorting, age-gap gradient, and the asymmetric marriage penalties by gender, highlighting how biological clocks and social norms jointly shape marital bargaining and the returns to waiting.

The first formal network theoretical model of maritime powers, using public source data and building on maritime commercial indicators developed in “Impact of the Belt and Road Initiative on Maritime Commercial Power,” (with K. Li, M. Jin, Y. Xiao, Z. Yang, and K. F. Yuen). In press at Transportation Research Part A: Policy and Practice.