Raising the price of sugar-sweetened sodas, coffees, teas and energy, sports and fruit drinks by an average of 31% reduced consumer purchases of those drinks by a third, according to a new analysis of restrictions implemented in five US cities.

“What we measured is how consumers change their consumption in response to price changes,” said study author Scott Kaplan, an assistant professor of economics at the US Naval Academy in Annapolis, Maryland.

“For every 1% increase in price, we found a 1% decrease in purchases of these products,” Kaplan said. “The decrease in consumer purchases occurred almost immediately after the taxes were put in place and stayed that way over the next three years of the study.”