In this paper--the first in a series of two papers that use data on 21 billion friendships from Facebook to study social capital--we measure and analyze three types of social capital by ZIP code in the United States: (i) connectedness between different types of people, such as those with low vs....

Low levels of social interaction across class lines have generated widespread concern and are associated with worse outcomes, such as lower rates of upward income mobility. Here, we analyze the determinants of cross-class interaction using data from Facebook, building upon the analysis in the...

Most listed firms are freestanding in the U.S, while listed firms in other countries often belong to business groups: lasting structures in which listed firms control other listed firms. Hand-collected historical data illuminate how the present ownership structure of the United States arose: (1)...