A large literature documents the developmental advantages of Protestantism over Catholicism, yet comparisons involving Eastern Orthodoxy remain scarce. This paper exploits an eighteenth-century natural experiment: the Habsburg-sponsored union that grafted Roman obedience onto the Romanian Orthodox rite, creating the Greek-Catholic Church. The new denomination rapidly established parishes, built schools, and trained a generation of clergy and lay intellectuals in Transylvania. Digitizing the full geography of its 1,211 parishes, I trace their effects on 3,181 contemporary localities. Instrumental variable estimation, using distance to the original episcopal seat in Alba Iulia, shows that villages with historical parish presence are today richer, host more firms, and produce more patents than otherwise similar places. Sequential g-estimation demonstrates that this premium is independent of the broader Habsburg institutional apparatus. By shifting the com-parison from Protestantism versus Catholicism to Catholic hybridity versus Eastern Orthodoxy, the findings highlight institutional adaptation as a source of long-run economic divergence.
Vlad Surdea‐Hernea (Thu,) studied this question.