Economists are pretty united against tariffs. There are lots of complicated arguments. Keeping things simple, one reason is that they are bad for welfare. President-elect Trump seems to imply that tariffs can raise a lot of government revenue. But in lieu of what? The Tax Foundation estimates that there is absolutely no way that tariffs can replace all revenue from income taxes. The primary reason that they cite is that imports compose a tiny portion of the potential tax base. There are plenty of goods and services produced domestically that wouldn’t be subject to the tariffs. Any time we add a tax exemption, we’re adding complication, higher compliance costs, and distorting consumption patterns, etc.
For this post I singularly focus on the tax revenue. In fact, let’s demonstrate what *maximizing* tax revenue looks like under three cases: 1) Closed economy with a tax, 2) Open economy with a tax, & 3) Open economy with a tariff. I’ll use some simple math to demonstrate my point. None of the particulars affect the logic. You’ll reach the same general results with different intercepts, slopes, etc. Let’s start with a domestic demand and domestic supply.
Closed Economy with a Tax
Whenever tax revenue is raised, there is a difference between the price paid by demanders and the price received by suppliers. In a closed economy a tax might be imposed on all goods. In these examples, I treat the tax as some dollar per-unit of output tax. But it’s a short jump to percent of spending taxes, and then another short jump to percent of income taxes. With this in mind, demanders pay more than the suppliers receive by the amount of the tax. Tax revenue is the tax rate times the number of units of output that are subject to the tax. That’s the thing we want to maximize.
Economist Writing Every Day 