Maybe parties don't matter?

Larry Bartels writes:

Considering America’s Depression-era politics in comparative perspective reinforces the impression that there may have been a good deal less real policy content to “throwing the bums out” than meets the eye. In the U.S., voters replaced Republicans with Democrats and the economy improved. In Britain and Australia, voters replaced Labor governments with conservatives and the economy improved. In Sweden, voters replaced Conservatives with Liberals, then with Social Democrats, and the economy improved. In the Canadian agricultural province of Saskatchewan, voters replaced Conservatives with Socialists and the economy improved. In the adjacent agricultural province of Alberta, voters replaced a socialist party with a right-leaning funny-money party created from scratch by a charismatic radio preacher, and the economy improved. In Weimar Germany, where economic distress was deeper and longer-lasting, voters rejected all of the mainstream parties, the Nazis seized power, and the economy improved. In every case, the party that happened to be in power when the Depression eased dominated politics for a decade or more thereafter. It seems farfetched to imagine that all these contradictory shifts represented well-considered ideological conversions. A more parsimonious interpretation is that voters simply-and simple-mindedly-rewarded whoever happened to be in power when things got better.