I (李国豪) am an incoming Presidential Fellow in the Department of Strategy and Policy in the National University of Singapore (NUS) Business School. In Summer 2025, I will be appointed an Assistant Professor.
In Fall 2023, I will visit the Cowles Foundation for Research in Economics at Yale University.
I graduated with my PhD in Economics from Princeton University. I spent my formative years in the US at the University of Chicago and Washington University in St. Louis.
I am an industrial organization economist, working broadly in the area of empirical market design. I perform design-based and model-based inference to study questions in urban economics, transportation economics, and the economics of digitization.
My research primarily concerns how to better design markets in (public) housing and transportation. A second strand of my research investigates entry, pricing, and intermediation on two-sided marketplaces.
Download my CV here.
(Click on paper descriptions to see abstracts)
dynamic allocation of public housing: Policy and spillovers
- Joint work with Andrew Ferdowsian and
- Revision in progress.
We consider the design of a large-scale public housing program where consumers face dynamic tradeoffs over apartments rationed via lotteries and prices. We show, theoretically and empirically, that changing rules complements increasing supply. First, we present a motivating example in which supplying more housing leads households to strategically delay their applications. By waiting for “better” developments arriving tomorrow, households forgo mediocre developments available today, resulting in more vacancies. Turning to the data from the mechanism, we formulate a dynamic choice model over housing lotteries and estimate it. Under the existing mechanism, we find that increasing supply fails to lower wait times. However, when a strategyproof mechanism is implemented, vacancies and wait times fall, but prices on the secondary market rise. Under this new mechanism, building more apartments lowers wait times and reduces the upward pricing pressure on the secondary market.
into two-sided markets shaped by platform-guided search
- Joint work with Leon Musolff.
- Awarded the Rising Star Paper Prize at the 20th International Industrial
Organization Conference (2022)
- In preparation for submission.
We evaluate the problem of firms that operate platforms matching buyers and sellers, while also selling goods on these same platforms. By being able to guide consumer search through algorithmic recommendations, these firms can influence market outcomes, a finding that has worried regulators. To analyze this phenomenon, we combine rich novel data about sales and recommendations on Amazon Marketplace with a structural model of intermediation power. In contrast to prior literature, we explicitly model seller entry. This feature enables us to assess the most plausible theory of harm from self-preferencing, i.e. that it is a barrier to entry. We find that recommendations are highly price elastic but favor Amazon. A substantial fraction of customers only consider recommended offers, and recommendations hence noticeably raise the price elasticity of demand. By preferring Amazon’s offer, the recommendation algorithm raises consumer welfare by approximately US$4.5 billion (since consumers also prefer these offers). However, consumers are made worse off if, as a consequence, the company raises prices by more than 7.8%. Furthermore, we find no evidence of consumer harm from self-preferencing through the entry channel. Nevertheless, entry matters. The algorithm raises consumer welfare in the short and medium run by increasing the purchase rate and intensifying price competition. However, these gains are mostly offset by reduced entry in the long run.
transit infrastructure and inequality
- Joint work with Brandon Joel Tan.
- See also our online appendix.
- New version (May 2023)! Submitted.
How does transit expansion impact welfare and inequality? Exploiting data covering the universe of transit farecard trips from Singapore, we propose a quantitative spatial model featuring heterogeneous worker groups and travel to consume non-tradable goods and services. First, we establish that low- and high-income workers live in and travel to different places. Second, we find that low-income workers are more sensitive to changes in travel time than their high-income counterparts. Third, since low-income workers are overwhelmingly employed in non-tradable sectors, we find that changes in consumption travel induced a spatial re-organization of low-income jobs in the city. We show that the Downtown Line resulted in large welfare gains for high-income workers, but near zero for low-income workers. All workers benefited from improved access to consumption opportunities, but low-income jobs in the non-tradable sector moved to less attractive workplaces. Abstracting from consumption travel underestimates the inequality effects five-fold.
Build to order: Endogenous supply in centralized mechanisms
- Joint work with Andrew Ferdowsian and
- Revision in progress.
How should the supply of public housing be optimally curated? Queuing mechanisms in the literature treat the supply of goods as exogenous. However, in practice, designers can often control the inflow of goods as well. We study a dynamic matching model based on the Singaporean housing allocation process. We show that endogenous supply radically changes the nature of the optimal mechanism. In this mechanism, a key feature is that under-demanded housing is overproduced relative to the static benchmark. Though competition leads to a decrease in efficiency when supply is exogenous, competition instead improves matching when supply is endogenous. Competition can be artificially generated through increasing the thickness of the market by batching applications. We show that doing so is a key feature of the optimal mechanism when the planner places a high weight on match quality.
Work in Progress
- Discovering lottery odds: Implications for public housing market design (with Andrew Ferdowsian and Yiying Tan)
- City design (with Brandon Joel Tan)
- Quotas or taxes? The case of automobiles (with Indranil Chakraborty and Tiffany Tsai)
- Expiring leases (with Andrew Ferdowsian)
- The Singaporean housing system
Here I provide sample syllabi for second-year graduate classes in Empirical Industrial Organization and Urban Economics.