Greater Bay Area
Market Design
Workshop 2026

Ride-hailing platforms increasingly use rank-based dispatch: peak-period compliance earns points that translate into lean-period priority. We study two consequences: an involution mechanism (rankings promote peak-time acceptance, expand hours and mileage, suppress unit pay, increase fatigue-related safety risk) and a collusion mechanism (rank becomes reputation capital that discourages multihoming, partitions the driver pool, and softens wage competition). We develop a dynamic model of rank-based dispatch and formally derive the involution and collusion mechanisms. Using driver surveys, municipal monitoring reports, and a staggered quasi-experiment around a cab platform's ranking intensification, we document significant empirical support. Findings motivate targeted regulation of rank-based incentives.

Inspired by major transition programs, this paper studies the design of exchange mechanisms within a framework that incorporates both distributional constraints and dual-priority-respecting constraints. We propose two mechanisms that match students to majors in an efficient way, while respecting each major's distributional constraints and dual-priority-respecting constraints. The efficient mechanisms are based on eligibility maximization (EM) and two processes for identifying improvement cycles — TiE cycles and ToE cycles.

Motivated by the pervasive need for privacy, we investigate the confidentiality of dynamic mechanisms that implement a given social choice function. We introduce two privacy criteria, intrusiveness and exposedness. A mechanism is confidential if and only if neither of the two proposed transformations (subtracting duplicate actions and obfuscating superfluous information) can be applied to the associated gradual mechanisms. We provide confidential mechanisms for the second-price auction rule and the hierarchical exchange rule.

We study the conditional acceptance mechanism in the standard school choice model. Equilibrium sets are nested in the cap and coincide with the stable set for kappa ≤ 2, but unstable equilibrium outcomes can arise for any kappa ≥ 3. Our main results compare conditional acceptance with deferred acceptance: Ergin-acyclicity is sufficient but not necessary for conditional acceptance to implement the set of stable matchings.

In 55 countries, volunteer, non-remunerated donations meet less than 22% of blood demand, necessitating replacement donor programs. Current first-come, first-served practices are inefficient. We introduce feasible schedule menus — a novel concept that enables flexible exchange rates — and propose weighted utilitarian mechanisms. Under suitable menus, these mechanisms are incentive compatible for donor revelation; priority mechanisms also ensure incentive compatibility for utility function revelation.

We experimentally examine to what extent non-truthtelling in strategy-proof matching mechanisms can be attributed to a failure of contingent thinking (FCT). When we remove the need to think contingently, we find no increase in truthtelling. If instead we inform applicants of contingency probabilities, removing the need to think contingently increases truthtelling. We conjecture non-truthtelling is instead caused by non-standard preferences or beliefs.

We study stability in matching markets with two-sided incomplete information. We first introduce a notion of stability based only on iterative reasoning about rational blocking behavior in the absence of communication. We then develop a refinement that allows for self-enforcing blocking agreements. We discuss the relationship between these two notions and their implications for matching under incomplete information.

Allocating public budgets to incentivize performance is difficult when absolute performance levels cannot be compared across heterogeneous units. This paper develops an axiomatic framework for budget allocation based on performance trajectories. We characterize families of rules that satisfy time consistency together with invariance conditions, and show how they govern treatment of historical performance and status-quo allocations.

India's affirmative action system — the world's largest — has been repeatedly reviewed by the Supreme Court of India. We formalize the legal principles established in Indra Sawhney (1992) and Ashoka Kumar Thakur (2008) as axioms and derive the corresponding allocation procedures. Our assignment rule eta* implements the Justice Bhandari remedy by reallocating unfilled OBC positions according to merit while holding the cutoff fixed, and merit-dominates every assignment rule consistent with the governing legal principles.

We study strategic application behavior in centralized university admissions. Using administrative data from a Chinese province, we document that students strategically submit portfolios of choices. Exploiting two sequential institutional reforms — an expansion in the number of choices and a shift from pre-exam to post-score preference submission — we find that the expansion shifts female students towards less selective first-choice universities, while post-score submission substantially improves targeting precision.

Many markets are regulated for paternalistic reasons. We develop a mechanism design theory of paternalistic regulation that derives the optimal policy instrument from primitives. When the planner corrects down valuations in a quasi-concave way, the optimal mechanism is either a posted-price rule or a simple rationing scheme. If the planner's valuation is monotone, sin taxes are optimal and achieve the first-best. Rationing emerges when the planner's valuation is non-monotone, and is diagnostic: whenever it is optimal, the second-best strictly falls short of the first-best.