What a difference a year makes: Americans ratcheted up spending last year after an income boost from the Trump tax cuts, but they’ve dialed back in 2019 in response to more economic uncertainty.

Consider retail sales. They’ve fallen in three of the past five months and have increased just 3.1% in the past 12 months. Last summer, retail sales were growing at a lusty 6% pace.

Read:Retail sales fall in April and show broad weakness in key part of the U.S. economy

What Americans spend at retailers represents only a portion of their overall consumption, but it offers a good cue of broader trends.

The slowdown in spending has taken place, even though wages and incomes are rising at the fastest clip in a decade and the unemployment rate has sunk to a 50-year low of 3.6%.

What’s going on?

For one thing, the Federal Reserve raised interest rates four times last year, making it more expensive to borrow to buy a home or to take out a business loan. The housing market was particularly hit hard.

The global economy also deteriorated, hurting demand for manufactured goods and other U.S. exports. Exacerbating the slowdown was a confrontation between the U.S. and China over trade rules that disrupted global supply chains and discouraged businesses from investing.

Read:The monster clash between U.S., China over trade dwarfs all other issues about the economy

Adding to the jitters was a meltdown in the U.S. stock market DJIA, +0.19% SPX, +0.29% in December that briefly stoked talk of recession and the 35-day partial government shutdown.

“Trade wars and equity market plunges are not great recipes for confidence-building, and these could weigh on the consumer in the weeks and months ahead,” MFR Inc. chief economist Joshua Shapiro said.

Economists doubt consumer spending will get much weaker given the strength of the labor market, but they also doubt it will match last year’s more robust pace.