Background: Kin effects can be difficult to distinguish from those of spatial proximity, since kin tend to live close to each other. Thus, past research showing correlations between the wealth of relatives may be showing the effects of proximity and shared locations, not the effects of kin.

Objective: What are the effects of kin and of spatial proximity upon wealth? This is studied both for fathers and sons and for brothers.

Methods: Data comes from a genealogical sample that has been linked to the US census of 1860. The genealogies allow us to identify fathers, sons, and brothers, information that is not available from the census itself. A Bayesian hierarchical approach can model family and spatial effects at the same time, thereby distinguishing them from each other.

Results: Data on fathers and sons is difficult to interpret from a single time. Many of the fathers in the census had died, so the sample size was small. A man's wealth was positively associated with his brothers' average wealth, even after their father had died. Therefore, there was evidence for lasting family effects; however, proximity to the other brothers was not related to an individual's wealth.

Conclusions: The family effects were stronger than the spatial effects at this time, even though this sample was highly mobile. Thus, there was evidence for family effects apart from spatial effects.

Comments: This study shows how Bayesian spatial analysis can be used to disentangle the effects of family from the effects of spatial location. The method was capable of distinguishing spatial from family effects.