Competing Social Influence in Contested Diffusion: Luther, Erasmus and the Spread of the Protestant Reformation

The spread of radical institutional change does not often result from onesided pro-innovation influence; countervailing influence networks in support of the status quo can suppress adoption. We develop a model of multiple and competing network diffusion. To apply the contesteddiffusion model to real data, we look at the contest between Martin Luther and Desiderius Erasmus, the two most influential intellectuals of early 16th-century Central Europe. Whereas Luther championed a radical reform of the Western Church that broke with Rome, Erasmus opposed him, stressing the unity of the Church. In the early phase of the Reformation, these two figures utilized influence networks of followers, affecting which cities in the Holy Roman Empire adopted reform. Using newly digitalized data on both leaders’ correspondence networks, their travels, the dispersion of their followers, and parallel processes of exchange among places through trade routes, we employ econometric tests and network simulations to test our theoretical model. We find that Luther’s network is strongly associated with the spread of the Reformation and that Erasmus’s network is associated with the stifling of the Reformation. This is consistent with a “fire-fighting†mechanism of contested diffusion, whereby the countervailing force suppresses innovations only after they have begun to spread.