All the stuff that makes life pricey these days, from high fuel costs to trade wars, means that grocery stores are charging more, too: grocery prices are up about 3% over the past year.But things look a bit different at the number one seller of groceries, Walmart. At the beginning of the year, Walmart said it rolled back prices on 7,200 items. Then, the company announced in its last earnings call that it did it again — on 11,000 more items. Many of them food items.“They're taking advantage of an increasingly distressed consumer,” said Mark Cohen, former director of retail studies at Columbia University.So, as grocery prices zig, Walmart zags — because everything’s getting more expensive. Electricity, gasoline, home insurance. So, Cohen said more people from higher and higher income brackets are joining the search to save money.“This is an opportunity for Walmart to capture consumers moving down market because they have less disposable income,” he said.Walmart is also better-positioned to cut prices than anyone else. For one thing, they got a massive windfall this year, according to Arun Sundaram, senior vice president of investment strategy at CFRA research.“They got nearly $3 billion of tariff refunds in Q2,” Sundaram said. “Walmart said that they were going to at least use some of the tariff refunds that they were expected to get to lower prices.”On top of that, Sundaram said it helps that Walmart sells more than just groceries.“I call these alternative revenue streams,” he said. “These are very profitable, high-margin revenue streams for Walmart, and they can actually take some of those profits and subsidize their core grocery business if they wanted to.”Kroger can’t exactly rely on apparel and housewares sales to lower grocery prices like Walmart can. Since Walmart is also the biggest grocer in the country, it’s got the whole economy-of-scale thing going on. “In addition to those operational efficiencies, just a lower cost of transportation procurement, marketing, and all the operations of the business,” said William Masters, an economics professor at Tufts University.Masters said these price cuts won’t last forever. He called them a classic end-of-summer promotion.“The temporary price cuts are hoped to bring in customers away from competitors and to have those customers stick,” Masters said.But the customers have to stick before Walmart starts raising prices again. Masters said Walmart’s strategy won’t work if price-comparison shopping is here to stay.