BACKGROUND Although kin marriage is widely practiced in the Middle East, its underlying motivations have not been thoroughly tested. METHODS We assess evidence for two economic rationales motivating kin unions using a national sample of Egyptians who wed between the 2006 and 2012 waves of the Egypt Labor Market Panel Surveys. The first rationale for kin marriage involves consolidating family property through the marriage of relatives; the second involves avoiding the costly outlays made when nonrelatives wed. RESULTS We find that respondents whose natal households owned agricultural land had higher relative risks of marrying a first cousin, and this relationship is significant for the overall sample and for men. Additionally, we find a positive association between value of natal household agricultural enterprise and marriage to a relative for men only. These findings provide limited evidence supporting the first rationale. For the second rationale, we find that women who wed relatives, reported lower bride's side matrimonial expenditures and lower deferred dower values. However, women who wed first cousins reported higher prompt dower values, indicating mixed support for the second rationale. CONTRIBUTION This study uses nationally representative longitudinal data with proper temporal ordering of key variables to statistically test two motivations for kin marriage. This analysis is carried out for Egypt, the most populous country of the world region containing some of the highest rates of kin marriage. Our results call into question two Salem & Shah: Economic rationales for kin marriage: Assessing the evidence using Egyptian panel data 546 http://www.demographic-research.org common assumptions about the economic rationales motivating kin marriage. We offer explanations for these unexpected findings in our conclusions.