When the US government imposed Section 232 tariffs on steel and aluminum imports back in 2018, the policy was framed, officially at least, as a national security measure. It was about preserving the integrity of critical domestic industries, or so the argument went. But nearly from the outset, economists, manufacturers, and policymakers began to debate—sometimes heatedly—whether the broader economic costs might outweigh the intended benefits. By 2022, enough time had passed to begin assessing the fallout with greater clarity, and the US International Trade Commission’s (ITC) study that year provided one of the more systematic looks at the issue. The findings? Well, they weren’t altogether surprising, though they did confirm in hard numbers what many suspected: the tariffs rippled far beyond primary steel and aluminum producers, with downstream manufacturers bearing a sizable share of the burden.
The ITC’s analysis painted a picture of supply chains straining under the weight of elevated input costs. Fabricators of everything from auto parts to industrial equipment reported higher expenses—not solely because of the tariffs themselves, but also because of knock-on effects in pricing dynamics. For firms operating on tight margins, or those locked into long-term supply contracts, adjusting wasn’t easy. There’s always a lag in these adjustments, and often it’s the smaller operators who find themselves squeezed hardest. What became clear from the data was that the tariffs had transmitted through the supply chain more efficiently than perhaps policymakers intended, with cost increases showing up in producer price indices (PPIs) across a range of sectors that, arguably, had little to do with national security.
For manufacturers seeking to quantify these impacts—whether to inform pricing strategies, negotiate supplier contracts, or prepare submissions for regulatory reviews—open customs data and PPI series offer a valuable starting point. US Customs and Border Protection’s public data sets provide granular detail on import volumes and declared values, which can be used to track shifts in sourcing patterns over time. Overlaying this with Bureau of Labor Statistics PPI data helps isolate periods where input costs diverged from historical trends. The analysis isn’t always straightforward, to be fair. External factors—pandemic disruptions, exchange rate movements, energy prices—muddy the waters. But even with these complications, a careful matching of customs entries with monthly or quarterly PPI changes can highlight periods where tariff effects were most pronounced.
One approach that some manufacturers have found useful is to break down cost transmission into stages. For instance, mapping price changes from raw material imports to semifinished goods (like coils or billets), and then onto finished components. It’s not a perfect science—there’s always the issue of time lags and inventory buffers—but it gives a clearer sense of where and how cost pressures accumulate. And it also provides data points that can support requests for tariff exemptions or adjustments, should firms choose to pursue them.
Where companies have struggled, at times, is in systematically capturing feedback from their own downstream partners. The ITC study relied in part on firm-level surveys to gather information on tariff impacts. But not all manufacturers have the internal mechanisms to do this well. For those looking to replicate or extend such efforts, designing a thoughtful survey for fabricators and sub-suppliers is crucial. Questions might cover changes in raw material sourcing, shifts in supplier relationships, observed price increases (both in percentage terms and absolute dollar amounts), and the extent to which additional costs have been passed through to customers. It’s easy to draft a survey that looks comprehensive on paper but yields little useful data. The key is clarity and focus. For example, rather than asking, “How have tariffs affected your business?”—which invites vague responses—it’s better to ask, “Since 2018, what has been the average percentage increase in your steel input costs attributable to tariffs?” or “Have you altered sourcing practices to mitigate tariff exposure, and if so, how?”
It’s also worth considering how to encourage honest participation. Downstream firms may be reluctant to share commercially sensitive information unless confidentiality is assured. And smaller players, in particular, may feel they lack the data to respond rigorously. Yet their insights are often the most telling. They’re closer to the pressure points, so to speak. Some manufacturers have experimented with anonymized, aggregated reporting to address this concern, though the effectiveness of this approach can vary depending on industry norms.
Interestingly, one undercurrent in discussions around the 232 tariffs has been the tension between domestic industrial policy goals and the realities of global supply chains. Even firms that supported the tariffs in principle—out of alignment with national security priorities or domestic capacity building—found themselves wrestling with unintended consequences. A fabricator might prefer to buy US-made steel, but if domestic supply couldn’t keep pace or if domestic mills raised prices sharply in response to the protection, choices narrowed. And so, even with patriotic intent, economic rationality often won out.
The ITC’s study didn’t settle the policy debate. It probably couldn’t have. But it did provide a firmer empirical foundation for future decisions. And for manufacturers still navigating these waters, leveraging open data—whether customs records, PPIs, or structured survey feedback—remains one of the best tools available for making sense of a complex, and at times frustrating, policy environment.