Join authors Glenn Hubbard and Tony O’Brien as they discuss how core economic principles illuminate two of the most pressing policy debates facing the economy today: tariffs and artificial intelligence. Drawing on a recent Supreme Court decision striking down broad tariff increases, Hubbard and O’Brien explain why economists view tariffs as taxes, who ultimately bears their burden, and how trade policy uncertainty shapes business decisions, inflation, and economic growth—bringing textbook concepts like tax incidence, intermediate goods, and GDP measurement vividly to life. The conversation then turns to AI, where they cut through market hype and dire predictions to place generative AI in historical context as a general‑purpose technology, comparing it to past innovations that transformed jobs without eliminating work. Along the way, they explore how AI can both substitute for and complement labor, why fears of mass unemployment are likely overstated, and what economists can—and cannot yet—say about AI’s long‑run effects on productivity, profits, and the labor market.
Category: Ch9: Comparative Advantage and the Gains from International Trade
New Real GDP Data Shows that Growth Slowed Substantially in the Fourth Quarter … or Did It?
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Recent macro data had been showing relatively strong growth in output and steady growth in employment. This morning’s release of the initial estimate of real GDP growth for the fourth quarter of 2025 from the Bureau of Economic Analysis (BEA) was expected to show continuing solid growth. (The report can be found here.) Instead, the BEA estimates that real GDP increased in the fourth quarter by only 1.4 percent measured at an annual rate. Growth was down sharply from the 4.4 percent increase in the third quarter of 2025. Economists surveyed by the Wall Street Journal had forecast a 2.5 percent increase. The following figure shows the estimated rates of GDP growth in each quarter beginning with the first quarter of 2021.
As the following figure—taken from the BEA report—shows, the decline in real government expenditures of –0.90 percent at an annual rate was the most important factor contributing to the slowing growth in real GDP during the fourth quarter. The decline in government expenditures is largely attributable to the federal government shutdown, which lasted from October 1, 2025 to November 12, 2025.
As we’ve discussed in previous blog posts, to better gauge the state of the economy, policymakers—including Fed Chair Jerome Powell—often prefer to strip out the effects of imports, inventory investment, and government expenditures—which can be volatile—by looking at real final sales to private domestic purchasers, which includes only spending by U.S. households and firms on domestic production. As the following figure shows, real final sales to domestic purchasers increased by 2.4 percent at an annual rate in the fourth quarter, which was well above the 1.4 percent increase in real GDP and also above the U.S. economy’s expected long-run annual real growth rate of 1.8 percent. Note also that real final sales to private domestic purchasers grew by 2.9 percent in the third quarter, during which real GDP grew by 4.4 percent, and by 1.9 percent in the first quarter of 2025, when real GDP declined by 0.6 percent. So this measure of output is more stable and likely is a better indicator of the underlying growth rate in the economy than is growth in real GDP.
The BEA report this morning also included quarterly data on the personal consumption expenditures (PCE) price index. The Fed relies on annual changes in the PCE price index to evaluate whether it’s meeting its 2 percent annual inflation target. The following figure shows headline PCE inflation (the blue line) and core PCE inflation (the red line)—which excludes energy and food prices—for the period since the first quarter of 2019, with inflation measured as the percentage change in the PCE from the same quarter in the previous year. In the fourth quarter of 2025, headline PCE inflation was 2.8 percent, up slightly from 2.7 percent in the third quarter. Core PCE inflation in the third quarter was 2.9 percent, unchanged from the third quarter. Both headline PCE inflation and core PCE inflation remained above the Fed’s 2 percent annual inflation target.
The following figure shows quarterly PCE inflation and quarterly core PCE inflation calculated by compounding the current quarter’s rate over an entire year. Measured this way, headline PCE inflation increased to 2.9 percent in the fourth quarter of 2025, up from to 2.8 percent in the third quarter. Core PCE inflation fell to 2.7 percent in the fourth quarter of 2025 from 2.9 percent in the third quarter. Measured this way, both core and headline PCE inflation were also above the Fed’s target.
Today was also notable for a decision from the U.S. Supreme Court that invalidated some of the Trump administration’s tariff increases that began to be implemented in April 2025. President Trump announced this afternoon that he would impose a new 10 percent across-the-board tariff, relying on Section 122 of the Trade Act of 1974, rather than on the International Emergency Economic Powers Act (IEEPA), which the Supreme Court ruled today did not authorize presidents to unilaterally impose tariffs.
Today’s developments appeared unlikely to have much effect on the views of the members of the Fed’s policymaking Federal Open Market Committee (FOMC). The FOMC is unlikely to lower its target for the federal funds rate at its next meeting on March 17–18. The probability that investors in the federal funds futures market assign to the FOMC keeping its target rate unchanged at that meeting increased only slightly from 94.6 percent yesterday to 96.0 percent this afternoon.
The United States Typically Runs Surpluses in Services as Well as Deficits in Goods
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A recent post on the blog of the Federal Reserve Bank of St. Louis reminds us that although the media and some policymakers tend to focus on the fact that the United States typically runs a deficit in trade in goods, it also typically runs a surplus in trade in services. We discuss these points in Economics, Chapter 9, Section 9.1 and Chapter 28, Section 28.1 (Macroeconomics, Chapter 7, Section 7.1 and Chapter 18, Section 18.1, and Microeconomics, Section 9.1). The first of the following figures shows U.S. net exports in services in dollar terms for the period from the first quarter of 1960 through the second quarter of 2025. The second figure show U.S. net exports in services as a percentage of U.S. GDP.
How does the United States compare to other countries? The following figure shows for 2024 the leaders in net exports of services for large economies (those with GDP of $1 trillion or more). The United States has largest value for net exports of services followed by the United Kingdom. China had negative net exports of services in 2024.
The following figure shows net exports in services as percentage of GDP among large economies. Measured this way, the largest net exporter of services is the United Kingdom, followed by Spain. The United States is included in graph (in red) for comparison and ranks ninth.
The following table from the St. Louis Fed’s blog posts shows the U.S. industries that export the most services.
The export of travel services represents largely foreign tourism in the United States. For example, if a family from France visits Walt Disney World in Florida, their spending would be included as an export of travel services.
Solved Problem: Using the Demand and Supply Model to Analyze the Effects of a Tariff on Televisions
Supports: Microeconomics, Macroeconomics, Economics, and Essentials of Economics, Chapter 4, Section 4.4
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The model of demand and supply is useful in analyzing the effects of tariffs. In Chapter 9, Section 9.4 (Macroeconomics, Chapter 7, Section 7.4) we analyze the situation—for instance, the market for sugar—when U.S. demand is a small fraction of total world demand and when the U.S. both produces the good and imports it.
In this problem, we look at the television market and assume that no domestic firms make televisions. (A few U.S. firms assemble limited numbers of televisions from imported components.) As a result, the supply of televisions consists entirely of imports. Beginning in April, the Trump administration increased tariff rates on imports of televisions from Japan, South Korea, China, and other countries. Tariffs are effectively a tax on imports, so we can use the analysis in Chapter 4, Section 4.4, “The Economic Effect of Taxes” to analyze the effect of tariffs on the market for televisions.
- Use a demand and supply graph to illustrate the effect of an increased tariff on imported televisions on the market for televisions in the United States. Be sure that your graph shows any shifts of the curves and the equilibrium price and quantity of televisions before and after the tariff increase.
- An article in the Wall Street Journal discussed the effect of tariffs on the market for used goods. Use a second demand and supply graph to show the effect of a tariff on imports of new televisions on the market in the United States for used televisions. Assume that no used televisions are imported and that the supply curve for used televisions is upward sloping.
Solving the Problem
Step 1: Review the chapter material. This problem is about the effect of a tariff on an imported good on the domestic market for the good. Because a tariff is a like a tax, you may want to review Chapter 4, Section 4.4, “The Economic Effect of Taxes.”
Step 2: Answer part a. by drawing a demand and supply graph of the market for televisions in the United States that illustrates the effect of an increased tariff on imported televisions. The following figure shows that a tariff causes the supply curve of televisions to shift up from S1 to S2. As a result, the equilibrium price increases from P1 to P2, while the equilibrium quantity falls from Q1 to Q2.
Step 2: Answer part b. by drawing a demand and supply graph of the market for used televisions in the United States that illustrates the effect on that market of an increased tariff on imports of new televisions. Although the tariff on imported televisions doesn’t directly affect the market for used televisions, it does so indirectly. As the article from the Wall Street Journal notes, “Today, in the tariff era, demand for used goods is surging.” Because used televisions are substitutes for new televisions, we would expect that an increase in the price of new televisions would cause the demand curve for used televisions to shift to the right, as shown in the following figure. The result will be that the equilibrium price of used televisions will increase from P1 to P2, while the equilibrium quantity of used televisions will increase from Q1 to Q2.
To summarize: A tariff on imports of new televisions increases the price of both new and used televisions. It decreases the quantity of new televisions sold but increases the quantity of used televisions sold.
NEW! 11-07-25- Podcast – Authors Glenn Hubbard & Tony O’Brien discuss Tariffs, AI, and the Economy
Glenn Hubbard and Tony O’Brien begin by examining the challenges facing the Federal Reserve due to incomplete economic data, a result of federal agency shutdowns. Despite limited information, they note that growth remains steady but inflation is above target, creating a conundrum for policymakers. The discussion turns to the upcoming appointment of a new Fed chair and the broader questions of central bank independence and the evolving role of monetary policy. They also address the uncertainty surrounding AI-driven layoffs, referencing contrasting academic views on whether artificial intelligence will complement existing jobs or lead to significant displacement. Both agree that the full impact of AI on productivity and employment will take time to materialize, drawing parallels to the slow adoption of the internet in the 1990s.
The podcast further explores the recent volatility in stock prices of AI-related firms, comparing the current environment to the dot-com bubble and questioning the sustainability of high valuations. Hubbard and O’Brien discuss the effects of tariffs, noting that price increases have been less dramatic than expected due to factors like inventory buffers and contractual delays. They highlight the tension between tariffs as tools for protection and revenue, and the broader implications for manufacturing, agriculture, and consumer prices. The episode concludes with reflections on the importance of ongoing observation and analysis as these economic trends evolve.
Pearson Economics · Hubbard OBrien Economics Podcast – 11-06-25 – Economy, AI, & Tariffs
08-16-25- Podcast – Authors Glenn Hubbard & Tony O’Brien discuss tariffs, Fed independence, & the controversies at the BLS.
In today’s episode, Glenn Hubbard and Tony O’Brien take on three timely topics that are shaping economic conversations across the country. They begin with a discussion on tariffs, exploring how recent trade policies are influencing prices, production decisions, and global relationships. From there, they turn to the independence of the Federal Reserve Bank, explaining why central bank autonomy is essential for sound monetary policy and what risks arise when political pressures creep in. Finally, they shed light on the Bureau of Labor Statistics (BLS), unpacking how its data collection and reporting play a vital role in guiding both public understanding and policymaking.
It’s a lively and informative conversation that brings clarity to complex issues—and it’s perfect for students, instructors, and anyone interested in how economics connects to the real world.
Glenn Discusses Tariffs on Firing Line
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Recently, Glenn appeared on the Firing Line program to discuss tariffs. Coincidentally, Margaret Hoover, the host of the program, is the great-granddaughter of Herbert Hoover. Herbert Hoover was the president who signed the Smoot-Hawley Tariff bill in 1930. We discussed the Smoot-Hawley Tariff in a recent blog post.
The U.S.-China Trade War Illustrated in Two Graphs from the Peterson Institute
Photo of U.S. President Donald Trump and China President Xi Jinping from Reuters.
The tit-for-tat tariff increases the U.S. and Chinese governments have levied on each other’s imports have reached dizzying heights today (April 11). The United States has imposed a tariff rate of 134.7 percent on imports from China, while China has imposed a tariff rate of 147.6 percent on imports from the United States. On all other countries—the rest of the world (ROW)—the United States imposes an average tariff rate of 10.5 percent, which is a sharp increase reflecting the Trump Administration’s imposition of a tariff of at least 10 percent on all countries. The government of China imposes a tariff rate of 6.5 percent on the ROW.
The Peterson Institute for International Economics (PIIE) is a think tank located in Washington, DC. Chad Brown, a senior fellow at PIIE, has created two charts that dramatically illustrate the current state of the U.S.-China trade war. The first chart shows the changes since the beginning of the first Trump Administration in 2017 in the tariff rates the countries have imposed on each other’s imports.
The second chart shows the percentage of each country’s exports to the other country that have been subject to tariffs. As of today, 100 percent of each country’s exports are subject to the other country’s tariffs.
Finally, we repeat a figure from an earlier blog post showing changes over time in the average tariff rate the United States levies on imports. The value for 2025 of 16.5 percent is an estimate by the Tax Foundation and assumes that the tariff rates that the Trump Administration announced on April 2 go into force, although the rates are currently suspended for 90 days—apart from those imposed on China. (An average tariff rate of 16.5 percent would be the highest levied by the United States since 1937.)
Thanks to Fernando Quijano for preparing this figure.
What Happened after Smoot-Hawley?
Congressman Willis Hawley of Oregon and Senator Reed Smoot of Utah (Photo from the U.S. Library of Congress via the Wall Street Journal)
Until last week, the most famous example of the United States dramatically increasing tariffs on foreign imports was the Smoot-Hawley Tariff, which was passed by Congress and signed into law by President Herbet Hoover in June 1930. The website of the U.S. Senate describes the bill as “among the most catastrophic acts in congressional history.”
Did the Smoot-Hawley Tariff cause the Great Depression? According to the National Bureau of Economic Research’s business cycle dates, the Great Depression began in August 1929, well before the passage of Smoot-Hawley. By June 1930, industrial production had already declined in the United States by more than 17 percent. So, even if the downturn had ended at that point it would still have been severe. The contraction phase of the Depression continued until March 1933, by which time industrial production had declined more than 51 percent. That was the largest decline in U.S. history
If Smoot-Hawley didn’t cause the Depression, did it contribute to the Depression’s length and severity? Most economists believe that it did by contributing to the collapse of the global trading system, thereby reducing U.S. exports, aggregate demand, and production and employment.
Some years ago, Tony wrote an overview of Smoot-Hawley that discusses its causes and effects in more detail. A key question in assessing the effects of Smoot-Hawley is the extent to which key trading partners of the United States raised their tariffs in retaliation. The clearest case is Canada, which in 1930 was the leading trading partner of the United States. Canadian Prime Minister William Lyon Mackenzie King and the Liberal Party significantly raised tariffs on U.S. imports in explicit retaliation for Smoot-Hawley. This journal article that Tony co-wrote with two Lehigh colleagues discusses the empirical evidence for this conclusion. (The link takes you to the Jstor site. You may be able to read or download the whole article by clicking on the link on that page and entering the name of your college or university.)
The Trump Administration seems to be attempting a major reordering of the global trading system. A Canadian prime minister in the 1930s tried something similar. Richard Bedford Bennett became prime minister after his Conservative Party defeated Mackenzie King’s Liberal Party in the 1935 Canadian election. Bennett hoped to replace the U.S. market with the markets in England and other countries in the British Commonwealth. He argued that, taken together, the Commonwealth countries had sufficient resources to be largely self-sufficient and need not rely on trade with non-Commonwealth countries. In the end, Bennett was unsuccessful for reasons that Tony and a Lehigh colleague explore in this journal article.
Douglas Irwin on Tariffs
Image generated by ChatGTP-4o illustrating tariffs.
Douglas Irwin, a professor of economics at Dartmouth College, may be the leading historian of international trade in the United States today. Irwin has posted at this link a useful overview of the economics of tariffs.
Irwin’s feed on X offers day-to-day commentary on current developments in the Trump Administration’s rapidly changing tariff policies. At the top of his X feed, you can find a free download of Clashing over Commerce, his 2019 history of U.S. foreign trade policy. At 862 pages, the book is the most thorough and comprehensive account available of the long-running political disputes in the United States over foreign trade.
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