More than a year after a new minimum wage took effect in Seattle– $12.50 an hour now for small employers, increasing to $15 an hour by January 2018–prices at most stores haven’t gone up.

Before the minimum wage law took effect, most retailers said they would have to charge more. So far, that hasn’t happened.

In a new report, researchers from the University of Washington presented data that showed “little or no evidence” of price increases in most sectors. Before the minimum wage law took effect, most retailers said they would have to charge more–and most low-wage workers were worried that they would have to spend more for necessities. So far, that hasn’t happened.

The researchers also checked the prices of things like rent and gas, because they wanted to understand how the law might affect the biggest expenses for low-income families. Those didn’t change either–not a surprising finding, since apartments and gas stations don’t rely on much labor.

The steady prices in the retail sector were more unexpected. “We looked in grocery stores, drugstores, and other types of retail outlets–we were focusing once again on places where your middle class or low-income families would be more likely to shop,” says Jacob Vigdor, a public policy professor at the University of Washington. “The fact that we didn’t find very many price increases in those types of outlets was a little bit more surprising to us.”

In some cases, store owners told the researchers that they couldn’t raise prices because of competition. “In some cases, you’ve got brick and mortar stores that are competing with Amazon.com–Seattle being the headquarters of Amazon, we really have a very dense on-the-ground network of delivery of almost any commodity you can find in almost any retail outlet,” he says.

One exception to the trend was restaurants, which raised prices 7%-9% because they rely so heavily on labor. Even there, however, owners sometimes found other ways to cut expenses as they paid workers more, such as closing during slow hours or asking customers to wait a little longer because fewer people are waiting tables.

“The marketplace is going to shake out those adjustments over the long run, and we’ll see which ones are sustainable because the restaurant can do them and not drive away customers,” Vigdor says.