S9 Ep45: Tariff Confusion

If you run a business that exports to the United States, how big is the tariff you have to pay? In 2025 that question was hard to answer. Between February and December, 53 separate announcements introduced, delayed, reinstated or changed US tariffs, with different countries and products pulled in or exempted each time.

Kalina Manova (UCL, CEPR) and her colleagues built a database of every one of those announcements, but they also measured  the confusion that those announcements created. She tells Tim Phillips about how tariff confusion has become a second tax on trade, as confusion puts off exporters: but it's one that raises no revenue.

On average, uncertainty about the actual tariff doubled the damage done to trade by the tariff hikes themselves. For some countries it tripled it. Does this result mean that, if the US cleared up the confusion by not changing its tariffs regularly, it could double tariff income for the same impact on trade?

The research behind this episode:

Manova, Kalina, Dennis Novy, Thomas Sampson, and Aaron Tang. 2026. "Tariff Confusion." CEPR Discussion Paper DP21688 (gated).

To cite this episode:

Phillips, Tim, and Kalina Manova. 2026. "Tariff Confusion." VoxTalks Economics (podcast).

About the guest

Kalina Manova is Professor of Economics at University College London and a Research Fellow at the Centre for Economic Policy Research. Her work spans global production networks and multinational activity, firm productivity and management, trade policy, and the financial frictions that shape international trade and investment. She holds an AB, AM and PhD from Harvard, and has previously held posts at Stanford, Princeton and Oxford.

Research cited in this episode

US Tariff Announcement Database (USTAD). The dataset Manova and her co-authors assembled by hand from US presidential executive orders and proclamations, recording all 53 tariff announcements of 2025 and tracing, for roughly 230 origin countries and more than 18,000 ten-digit product categories, the statutory tariff in place each month.

The four confusion measures. With no direct way to measure confusion, the paper proxies it four ways: the cumulative number of relevant announcements a firm had to track; the number of possible tariff calculations those announcements could produce (labelled tariff mess, defined as two to the power of the number of announcements); the highest tariff a firm might infer if it heard only the bad news (tariff max); and how far that worst case sits above the true statutory rate (tariff miss).