Protestantism and economic growth

Among Christians, Protestants have a reputation of hard workers. This is motivated by the preachings of the early reformers who have emphasized literacy and hard work, to the disadvantage of wasteful fun and decorum. This was quite a break from Catholicism, where decorum and the arts are very important. I am likely not alone in thinking that this explains why the South of Europe, predominantly Catholic, is poorer than the North.

Davide Cantoni makes me doubt that now but using a dataset that has fewer confounding factors than European national data: the Holy German Empire. Indeed, it was fractures in many fiefdoms of various religious orientations. Of course, economic data is rather limited for the sample periods of 1300 to 1900, so Cantoni does what economic historians typically do in such a situation: use population data, a presumably good proxy for economic development in a Malthusian world. There is rather good data for cities, and we know how they switched their religious denomination over time. And Cantoni finds nothings. No matter how he turns the data, Protestantism has no impact. Why? Maybe because we think of the teachings of Calvin when thinking about Protestantism, while Calvin was of limited impact? But what about the emphasis on literacy?