Selected Work in Progress
A Quantitative Model of Relational Contracts in Trade
Most international trade takes place in long-term buyer–seller relationships that expand gradually over time. A growing body of empirical evidence suggests that this pattern may reflect the importance of relational contracting: when formal enforcement is limited, continued trade itself provides incentives. Such self-enforcing relationships make trade adjustment inherently dynamic—new matches must build trust and scale from scratch—yet the quantitative trade models used to study shocks are typically static or sacrifice tractability when dynamics are introduced. I develop a dynamic multi-country general-equilibrium model that embeds optimal relational contracts within a tractable Eaton–Kortum-style framework. The model generates endogenous relationship deepening—quantities grow with relationship age—as an equilibrium outcome of self-enforcing incentives. I show that this optimal age profile scales linearly with the surplus, allowing the model to aggregate cleanly. The transition path after a shock is therefore straightforward to compute using exact hat algebra, and steady-state trade shares coincide with a static Eaton-Kortum model with endogenous origin-specific wedges. The new parameters governing the contracting friction can be estimated using increasingly available firm-to-firm trade data.
The Impact of Regional Integration on Trade and Supply Chains: Evidence from a VAT Reform in India (with Tishara Garg)
We use a landmark 2017 fiscal reform in India to quantify the gains to regional economic integration and to study how this affects the organization of supply chains. Using district-level data aggregated from firm-to-firm VAT transactions for the entire of India, we first show in the cross-section that state borders are comparable to country borders in other settings, with trade decreasing by 76% at the border. We then use event-study style regressions derived from a standard quantitative trade model to study the reform—which eliminated countrywide tax-induced interstate trading costs—and find that it increased interstate trade by 15% on average. With this estimated elasticity, the model implies that the reform increased aggregate GDP by 1% on average, with almost all districts experiencing gains. To examine how supply chains responded—including the extent to which firms shifted towards a more "hub and spokes" network, as in the classic proximity-concentration tradeoff—we are currently exploiting the micro-level firm-to-firm VAT data.