A Brief Overview of Tariffs

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A tariff is a tax a government imposes on imports. Since the end of World War II, high-income countries have only occasionally used tariffs as an important policy tool. The following figure shows how the average U.S. tariff rate, expressed as a percentage of the value of total imports, has changed in the years since 1790. The ups and downs in tariff rates reflect in part political disa-greements in Congress. Generally speaking, through the early twentieth century, members of Congress who represented areas in the Midwest and Northeast that were home to many manufacturing firms favored high tariffs to protect those industries from foreign competition. Members of Congress from rural areas opposed tariffs, because farmers were primarily exporters who feared that foreign governments would respond to U.S. tariffs by imposing tariffs on U.S. agricultural exports. From the pre-Civil War period until after World War II the Republicans Party generally favored high tariffs and the Democratic Party generally favored low tariffs, reflecting the economic interests of the areas the parties represented in Congress. (Note: Because the tariffs that the Trump Administration will end up imposing are still in flux, the value for 2025 in the figure is only a rough estimate.)

By the end of World War II in 1945, government officials in the United States and Europe were looking for a way to reduce tariffs and revive international trade. To help achieve this goal, they set up the General Agreement on Tariffs and Trade (GATT) in 1948. Countries that joined the GATT agreed not to impose new tariffs or import quotas. In addition, a series of multilateral negotiations, called trade rounds, took place, in which countries agreed to reduce tariffs from the very high levels of the 1930s. The GATT primarily covered trade in goods. A new agreement to cover services and intellectual property, as well as goods, was eventually negotiated, and in January 1995, the GATT was replaced by the World Trade Organization (WTO). In 2025, 166 countries are members of the WTO.

As a result of U.S. participation in the GATT and WTO, the average U.S. tariff rate declined from nearly 20% in the early 1930s to 1.8% in 2018. The first Trump Administration increased tariffs beginning in 2018, raising the average tariff rate to 2.5%. (The Biden Administration continued most of the increases.) In 2025, the second Trump Administration’s substantial increases in tariffs raised the average tariff rate to the highest level since the 1940s.

Until the enactment in 1913 of the 16th Amendment to the U.S. Constitution, which allowed for a federal income tax, tariffs were an important source of revenue to the federal government. As the following figure shows, in the early years of the United States, more than 90% of federal government revenues came from the tariff. As tariff rates declined and federal income and payroll taxes increased, tariffs declined to only 2% of federal government revenue. It’s unclear yet how much tariff’s share of federal government revenue will rise as a result of the Trump Administration’s tariff increases.

The effect of tariff increases on the U.S. economy are complex and depend on the details of which tariffs are increased, by how much they are increased, and whether foreign governments raise their tariffs on U.S. exports in response to U.S. tariff increases. We can analyze some of the effects of tariffs using the basic aggregate demand and aggregate supply model that we discuss in Macroeconomics, Chapter 13 (Economics, Chapter 23). We need to keep in mind in the following discussion that small increases in tariffs rates—such as those enacted in 2018—will likely have only small effects on the economy given that net exports are only about 3% or U.S. GDP.

An increase in tariffs intended to protect domestic industries can cause the aggregate demand curve to shift to the right if consumers switch spending from imports to domestically produced goods, thereby increasing net exports. But this effect can be partially or wholly offset if trading partners retaliate by increasing tariffs on U.S. exports. When Congress passed the Smoot-Hawley Tariff in 1930, which raised tariff rates to historically high levels, retaliation by U.S. trading partners contributed to a sharp decline in U.S. exports during the early 1930s.

International trade can increase a country’s production and income by allowing a country to specialize in the goods and services in which it has a comparative advantage. Tariffs shift a country’s allocation of labor, capital, and other resources away from producing the goods and services it can produce most efficiently and toward producing goods and services that other countries can produce more efficiently. The result of this misallocation of resources is to reduce the productive capacity of the country, shifting the long-run aggregate supply curve (LRAS) to the left.

Tariffs raise the prices of U.S. imports. This effect can be partially offset because tariffs increase the demand for U.S. dollars relative to trading partners’ currencies, increasing the dollar exchange rate. Because a tariff effectively acts as a tax on imports, like other taxes its incidence—the division of the burden of the tax between sellers and buyers—depends partly on the price elasticity of demand and the price elasticity of supply, which vary across the goods and services on which tariffs are imposed. (We discuss the effects of demand and supply elasticity on the incidence of a tax in Microeconomics, Chapter 17, Section 17.3.)

About two-thirds of U.S. imports are raw materials, intermediate goods, or capital goods, all of which are used as inputs by U.S. firms. For example, many cars assembled in the United States contain imported parts. The popular Ford F-Series pickup trucks are assembled in the United States, but more than two-thirds of the parts are imported from other countries. That fact indicates that the automobile industry is one of many U.S. industries that depend on global supply chains that can be disrupted by tariffs. Because tariffs on imported raw materials, parts and other intermediate goods, and capital goods increase the production costs of U.S. firms, tariffs reduce the quantity of goods these firms will produce at any given price. In terms of the aggregate demand and aggregate supply model , a large unexpected increase in tariffs results in an aggregate supply shock to the economy, shifting the short-run aggregate supply curve (SRAS) to the left.

Our thanks to Fernando Quijano for preparing the two figures.

Want a Raise? Get a New Job

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It’s become clear during the past few years that most people really, really, really don’t like inflation. Dating as far back as the 1930s, when very high unemployment rates persisted for years, many economists have assumed that unemployment is viewed by most people as a bigger economic problem than inflation. Bu the economic pain from unemployment is concentrated among those people who lose their jobs—and their families—although some people also have their hours reduced by their employers and in severe recessions even people who retain their jobs can be afraid of being laid off.

Although nearly everyone is affected by an increase in the inflation rate, the economic losses are lower than those suffered by people who lose their jobs during a period in which it may difficult to find another one. In addition, as we note in Macroeconomics, Chapter 9, Section 9.7 (Economics, Chapter 19, Section 19.7), that:

“An expected inflation rate of 10 percent will raise the average price of goods and services by 10 percent, but it will also raise average incomes by 10 percent. Goods and services will be as affordable to an average consumer as they would be if there were no inflation.”

In other words, inflation affects nominal variables, but over the long run inflation won’t affect real variables such as the real wage, employment, or the real value of output. The following figure shows movements in real wages from January 2010 through September 2024. Real wages are calculated as nominal average hourly earnings deflated by the consumer price index, with the value for February 2020—the last month before the effects of the Covid pandemic began affecting the United States—set equal to 100. Measured this way, real wages were 2 percent higher in September 2024 than in February 2020. (Although note that real wages were below where they would have been if the trend from 2013 to 2020 had continued.)

Although increases in wages do keep up with increases in prices, many people doubt this point. In Chapter 17, Section 17.1, we discuss a survey Nobel Laurete Rober Shiller of Yale conducted of the general public’s views on inflation. He asked in the survey how “the effect of general inflation on wages or salary relates to your own experience or your own job.” The most populat response was: “The price increase will create extra profifs for my employer, who can now sell output for more; there will be no increase in my pay. My employer will see no reason to raise my pay.”

Recently, Stefanie Stantcheva of Harvard conducted a survey similar to Schiller’s and received similar responses:

“If there is a single and simple answer to the question ‘Why do we dislike inflation,’ it is because many individuals feel that it systematically erodes their purchasing power. Many people do not perceive their wage increases sufficiently to keep up with inflation rates, and they often believe that wages tend to rise at a much slower rate compared to prices.”

A recent working paper by Joao Guerreiro of UCLA, Jonathon Hazell of the London School of Economics, Chen Lian of UC Berkeley, and Christina Patterson of the University of Chicago throws additional light on the reasons that people are skeptical that once the market adjusts, their wages will keep up with inflation. Economists typically think of the real wage as adjusting to clear the labor market. If inflation temporarily reduces the real wage, the nominal wage will increase to restore the market-clearing value of the real wage.

But the authors of thei paper note that, in practice, to receive an increase in your nominal wage you need to either 1)ask your employer to increase your wage, or 2) find another job that pays a higher nominal wage. They note that both of these approachs result in “conflict”: “We argue that workers must take costly actions (‘conflict’) to have nominal wages catch up with inflation, meaning there are welfare costs even if real wages do not fall as inflation rises.” The results of a survey they undertook revealed that:

“A significant portion of workers say they took costly actions—that is, they engaged in conflict—to achieve higher wage growth than their employer offered. These actions include having tough conversations with employers about pay, partaking in union activity, or soliciting job offers.”

Their result is consistent with data showing that workers who switch jobs receive larger wage increases than do workers who remain in their jobs. The following figure is from the Federal Reserve Bank of Cleveland and shows the increase in the median nominal hourly wage over the previous year for workers who stayed in their job over that period (brown line) and for workers who switched jobs (gray line).

Job switchers consistently earn larger wage increases than do job stayers with the difference being particularly large during the high inflation period of 2022 and 2023. For instance, in July 2022, job switchers earned average wage increases of 8.5 percent compared with average increases of 5.9 percent for job stayers.

The fact that to keep up with inflation workers have to either change jobs or have a potentially contentious negotiation with their employer provides another reason why the recent period of high inflation led to widespread discontent with the state of the U.S. economy.