Rerouting to Evade Tariffs - Our Latest Study

Tariffs and their impacts we have been researching for several decades now because of the relevance of the topic as well as the scientific interest in the mathematical modeling of supply chain networks and international trade. Furthermore, there are different types of tariffs, including unit tariffs, ad valorem tariffs, and even tariff rate quotas. We have studied the impacts of tariffs in perfectly competitive contexts such as spatial price equilibrium problems as well as in oligopolistic markets.

Recently, because of the escalating trade wars and imposition of various retaliatory tariffs in the second Trump administration, our research has included rerouting to evade tariffs. This topic has been quite newsworthy; see, for example, this article in The New York Times, which was published today: https://www.nytimes.com/2025/05/24/business/vietnam-china-transshipment.html

My paper, "Multicommodity Trade, Tariffs, and Rerouting," co-authored with my Isenberg School PhD student, Samirasadat "Samira" Samadi, was accepted in the very special volume: Convex and Variational Analysis with Applications: In Honor of Terry Rockafellar’s 90th Birthday. Panos M. Pardalos and Themistocles M. Rassias, Editors, Springer Nature Switzerland AG.

It was an honor to have been invited to contributed to this edited volume in honor of the amazing Professor Rockafellar, a giant in the optimization and variational inequalities.

A preprint of our paper can be downloaded from the Supernetwork Center website: https://supernet.isenberg.umass.edu/articles/MulticommodityTradeTariffsandRerouting.pdf

The case study in the paper focuses on tea, which is produced in both China and Vietnam, and, in our numerical examples, can be rerouted, with associated additional costs (although it is illegal) to demand markets. It is important to model and to quantify trade-offs associated with such illicit tariff evasion in order to provide policy- and decision-makers with insights for interdiction purposes. Our research continues.

Three Papers Accepted in One Week!

My Mother always said that "good news comes in threes" and this week we certainly had some much appreciated good news.

My paper, "NetwORks and Policies: OR to the Rescue," which is based on the Blackett Lecture that I delivered at The Royal Society in London, England on December 5, 2024, thanks to The Operational Research Society, was accepted for publication in the Journal of the Operational Research Society. And, incredibly, I received the galleys of the paper yesterday (a Saturday) and they were in great shape. Below is the first page.

And, since the Blackett Lecture experience was so special I include a collage below made of photos from the event, with deep gratitude for all that took part.

Many thanks also to The Operational Research Society for posting my Blackett Lecture online on Youtube: https://www.youtube.com/watch?v=S-LsIEsi-m0

Also, we heard from the International Transactions in Operational Research that the paper, "Integrated Crop and Cargo War Risk Insurance: Application to Ukraine," that I co-authored with my PhD student Ismael Pour and Professor Borys Kormych of the Odesa Law Academy in Ukraine, was accepted for publication. We hope to receive the galleys soon. Professor Kormych is a Virtual Scholar in our terrific UMass Amherst - Kyiv School of Economics (KSE) partnership. He was in the first cohort and is also in the second cohort. You can read more about the Virtual Scholars and their Faculty Hosts at the Isenberg School of Management here: https://www.umass.edu/global-affairs/news/kyiv-school-economics-and-university-massachusetts-amherst-launch-second-round-virtual-scholar

We heard the good news shortly after Ismael Pour presented the paper in the doctoral seminar in Management Science that I am teaching this semester. We took the nice photo below with him and Yongdong Chen and Samira Samadi (both also PhD students in the seminar) after Ismael's presentation.

Ismael will present this paper at the POMS Conference in Atlanta next month.

Also, Samira (full first name is Samirasadat) and I got the paper, "Multicommodity Trade, Tariffs, and Rerouting," accepted in a very special volume: Convex and Variational Analysis with Applications: In Honor of Terry Rockafellar’s 90th Birthday. Panos M. Pardalos and Themistocles M. Rassias, Editors, Springer Nature Switzerland AG. This is a very interesting and timely paper, given the trade wars that are happening now in real time. It discusses the evasion of tariffs and impacts through rerouting, with minimum processing, except for repackaging/relabeling in other countries.

We are grateful to the Editors and reviewers of our papers.