The detailed temporal variation of the proportion of degree holders shows that fewer of them had a northeastern hometown when the region was more politically independent. Only one "changepoint" was detected, so that the downward tendency was the only significant tendency. 4/7

The center of examination success within the northeastern region shifted southwestward from the northeastern part of the region, where many great
clans originated from but became highly independent in the late Tang. This result corresponds to the decline of the great clans. 3/7

We assembled a list of "hometowns" (further explained below) of each degree holder in the civil service examinations, and tracked the geographical distribution of their hometowns. We found the center of examination success moved away from the autonomous northeastern region. 2/7