Research

The transport sector is the backbone of international trade and has faced multiple disruptions in recent years. This paper studies how substitution across transport modes shapes international trade, welfare, and carbon emissions. Motivated by recent disruptions to air and maritime transport, I develop a quantitative multicountry trade model with multiple transport modes and endogenous congestion costs. I estimate the elasticity of substitution between transport modes at the country-pair level using the closure of Russian airspace as a quasi-natural experiment. I find an average elasticity of substitution between air and sea transport of 2.6. Counterfactual simulations show that allowing for mode substitution attenuates welfare losses from mode-specific transport shocks. However, since transport modes differ in carbon intensity, substitution also affects the environmental impact of trade and can weaken the effectiveness of environmental policies.
Presented at: ETSG, UEA European Meeting, GEP-CEPR Postgrad Conference, RIEF, EAYE, SETC, CEP/Warwick Junior Trade Workshop, Napoli Parthenope, Midwest Trade Conference, Norwegian School of Economics, World Bank Annual Conference on Transport Economics 2025.

We study how the interplay between oligopoly in the transportation industry and oligopsony power retained by non-atomistic importers affects the transmission of trade policy. Using Chilean customs data, we document strong concentration among carriers and importers and show that freight prices are determined through bilateral bargaining under two-sided market power. We estimate a trade model that endogenizes transportation costs by embedding oligopoly and oligopsony in the transport sector, along with bilateral bargaining. We find sizable carrier markups, partially offset by importer bargaining power. Embedding this mechanism into a quantitative trade model, we find that the endogenous response of transportation costs reduces the welfare cost of tariffs by 50% compared to the standard case of iceberg trade costs. This effect is primarily driven by decreasing returns to scale in carriers’ supply. Bargaining, in turn, plays a central role in shaping price levels and market allocations in the transportation sector.
Awards: Young Economist Award at 17th FIW International Economics Conference

This paper examines how transport mode shapes the geography of exchange rate pass-through (ERPT) within Global Value Chains. Using transaction-level customs data from the Bangladeshi garment sector (2018–2024), we exploit the sharp depreciation of the Bangladeshi Taka in 2022 to compare maritime and air-based trade corridors through Chittagong seaport and Dhaka airport. We show that ERPT to exporter prices is incomplete on average and systematically lower in buyer–seller relationships that rely more intensively on air transport. This differential is concentrated in destinations and products where delivery speed is especially valuable, notably European fast-fashion markets.

Brexit is a striking example of a potentially new era of trade disintegration. We estimate its effect on UK-EU goods trade using monthly bilateral trade data for 50 countries at the HS2 product level. Under various de-trending approaches, we find that the shift from EU membership arrangements to the Trade and Cooperation Agreement (TCA) in January 2021 caused a 17–18% fall in UK-EU trade. However, the longer-run effect, comparing pre-referendum with post-TCA trade, is sensitive to how trends are included, as estimates for the interim period between the referendum and Brexit vary substantially by trend choice. By product type, TCA implementation mainly reduced trade in consumer and intermediate goods, with no significant effect on capital goods. Further, we find no clear correlation between the trade effects and the goods-level trade elasticities reported by Fontagné et al. (2022).