Service Sector Growth Limits Fed Interest Rate Impact

A 1 percentage point shift in interest rates now affects manufacturing output three times more than service sector output, according to recent economic research. This disparity suggests that Federal Reserve policy changes may have a diminished impact on overall economic activity and inflation as the U.S. economy continues to evolve.

The service sector expanded from 73.9 percent of gross domestic product in 2000 to 79.7 percent in 2024. This nearly 6 percentage point increase reflects structural changes in how Americans spend their money. The shift is driven by rising incomes, which lead consumers to purchase more services relative to durable goods, and higher productivity in manufacturing, which raises the relative price of services.

Demographics play a central role in this trend. Older households consume more healthcare, financial services, restaurants, and travel, while younger households spend more on vehicles, housing, and durable goods. Research by economists Cravino, Levchenko, and Rojas determined that 20 percent of the increase in the service sector's share of total U.S. expenditures is driven by these older demographics.

Jaeho Lee, an economist who analyzed data from multiple industrialized countries, found that a 1 percentage point rise in the population share of people aged 65 and older increases the service sector's share of total output by slightly more than 1 percentage point. In the same scenario, the manufacturing share of output declines by 1 percentage point.

The Federal Reserve aims to maintain maximum employment and price stability, often through adjustments to interest rates. These rates influence the economy primarily by altering the cost of capital. Manufacturing is more capital intensive than the service sector, meaning businesses in manufacturing face higher costs when interest rates rise. Additionally, consumers frequently use credit to purchase manufactured items like cars and appliances, making demand for these goods more sensitive to rate changes.

In contrast, the service sector is less dependent on capital investment and credit. Lee's analysis shows that because of this structural difference, monetary policy tools have a weaker effect on services. As the service sector grows, the overall impact of interest rate changes on the economy shrinks. This implies that the Fed may need to implement larger rate adjustments to achieve the same reduction in demand and inflation.

Robert Krol, an emeritus professor of economics at California State University, Northridge, notes that recent shifts in trade, immigration, and fiscal policy already complicate the Fed's task. The aging population adds another layer of complexity. As the economy relies more on services, the traditional mechanisms for controlling inflation become less potent, requiring policymakers to account for these changing consumption patterns in their strategic planning.