Research

Current Research Agenda

My research examines how U.S. trade policy, tariffs, and supply-chain disruptions affect manufacturing outcomes, with a focus on the vehicle sector and related industrial supply chains. This research agenda combines product-level trade data, tariff exposure measures, public policy documentation, applied econometrics, and machine-learning tools to study how policy shocks propagate through production networks.

The agenda is organized around two publicly available working papers, one working paper currently under review at a peer-reviewed journal, supporting dashboards, and future firm-level research. These papers trace a connected trajectory: an early vehicle-sector application and a supporting policy dataset motivated the development of a more rigorous triple-difference design, with firm-level extensions planned next.

Working Papers

Where Do Tariff Shocks Propagate? Evidence on Production, Prices, and Shipments from Section 301 China Tariffs

Alfredo Sosa
Working Paper, 2026
Under review at a peer-reviewed journal. Available at SSRN.

This paper estimates the causal effects of the 2018–2019 Section 301 China tariffs on U.S. manufacturing production, producer prices, and nominal shipments. Using monthly NAICS-4 data, the analysis combines a continuous tariff-exposure measure with a triple-difference design that uses world, non-China import penetration as the control dimension.

The primary evidence comes from the FRED industrial-production panel: greater tariff exposure is associated with a statistically significant decline in real manufacturing activity. The producer-price results are suggestive of pass-through but remain statistically inconclusive under bootstrap inference. In the primary specification, the nominal-shipments estimates also point to a negative effect, though this result is imprecisely estimated. Together, the findings suggest that tariffs imposed on Chinese imports can raise cost pressures and weaken real activity in more exposed U.S. manufacturing industries.

Links:
Download Paper (PDF)
SSRN Abstract Page
DOI
Replication data archived at Zenodo: 10.5281/zenodo.21764320 (files under embargo until August 2, 2027; DOI is citable now).

Manuscript is under review at a peer-reviewed journal.

Suggested citation:
Sosa, Alfredo. 2026. Where Do Tariff Shocks Propagate? Evidence on Production, Prices, and Shipments from Section 301 China Tariffs. Working paper; under review at a peer-reviewed journal. Available at SSRN: https://ssrn.com/abstract=7216878 or https://doi.org/10.2139/ssrn.7216878.

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The Impact of Section 301 Tariffs on U.S. Vehicle Production and Sales: Evidence from HS6-Level Exposure and Dynamic Difference-in-Differences

Alfredo Sosa
Working Paper, 2026
Available at SSRN

This paper examines how the 2018 to 2019 U.S. Section 301 tariffs affected downstream outcomes in the commercial and light vehicle sectors. Using monthly data and an HS6-level import-weighted tariff exposure index, the analysis combines continuous-treatment difference-in-differences models with event-study specifications to trace the dynamic effects of tariff exposure on production and sales.

The results show that higher tariff exposure is associated with declines in production in both the commercial and light vehicle sectors. By contrast, nominal vehicle sales display more mixed responses across specifications. Event-study evidence indicates that these effects emerge after tariff implementation rather than reflecting pre-existing trends. Taken together, the findings suggest that tariffs imposed on upstream supply chains are associated with weaker downstream production outcomes, even when nominal sales appear comparatively stable.

Note: this early specification’s standard errors rely on a static, cross-sectional exposure measure repeated across the panel period, which likely overstates inferential precision in the baseline estimates. The triple-difference design in the working paper above (Where Do Tariff Shocks Propagate?) addresses this limitation directly and is the methodologically primary result in this research program.

Links:
Download Paper (PDF)
SSRN Abstract Page
DOI

Suggested citation:
Sosa, Alfredo. 2026. The Impact of Section 301 Tariffs on U.S. Vehicle Production and Sales: Evidence from HS6-Level Exposure and Dynamic Difference-in-Differences. Available at SSRN: https://ssrn.com/abstract=6455558 or https://doi.org/10.2139/ssrn.6455558.

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A Tariff Exposure Dataset for the U.S. Vehicle Supply Chain: Policy Evidence from the 2025–2026 Tariff Expansions

Alfredo Sosa
Working Paper, 2026
Available at SSRN

Earlier vehicle-sector study within the broader Section 301 research agenda.

This paper documents the expansion of U.S. tariff policy during 2025 to 2026 and constructs a structured dataset measuring tariff exposure across the commercial and light vehicle supply chain. The project compiles information from Federal Register notices, administrative actions, and public trade data to organize recent tariff changes into a transparent product-level framework.

The paper focuses on Section 301 expansions, Section 232 measures, antidumping and countervailing duty actions, and related policy developments. By transforming fragmented policy documents into a structured dataset, the project provides a foundation for measuring the timing, intensity, and sectoral distribution of tariff exposure across vehicle-related industries.

The paper also documents stylized facts on production, sales, prices, employment, and supply-chain conditions during the tariff expansion period. These patterns provide descriptive evidence on how tariff policy interacts with input-cost pressures, trade flows, and manufacturing outcomes.

This project serves as a data foundation for ongoing empirical work on trade policy and supply chains. By providing a structured measure of tariff exposure, it supports future causal analysis of how tariff shocks propagate through industrial production networks.

Links:
Download Paper (PDF)
SSRN Abstract Page
DOI

Suggested citation:
Sosa, Alfredo. 2026. A Tariff Exposure Dataset for the U.S. Vehicle Supply Chain: Policy Evidence from the 2025–2026 Tariff Expansions. Available at SSRN: https://ssrn.com/abstract=6648679 or https://doi.org/10.2139/ssrn.6648679.

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Firm-Level Evidence on Tariff Exposure and U.S. Manufacturing Outcomes

Future research

Building on the policy documentation and tariff-exposure datasets described in the preceding working papers, this project will extend the analysis to firm-level outcomes.The goal is to examine how tariff exposure affects production, sales, investment, and performance across heterogeneous U.S. manufacturers.

The analysis will use policy variation from recent tariff actions to implement causal identification strategies, including difference-in-differences and related empirical designs. This work is part of a broader research agenda linking public trade-policy data to measurable outcomes in U.S. manufacturing and supply chains.

Related Empirical Projects

Machine Learning, Forecasting, and Policy Simulation

In parallel with the working papers, I am developing machine-learning tools to study forecasting performance, counterfactual prediction, and policy simulation in the context of U.S. vehicle production and tariff exposure. These projects complement the core research agenda by providing predictive and scenario-based evidence.

Related dashboards and methodological memos are available on the Machine Learning and Dashboards pages.