Theoretical debates about the efficiency of sharecropping discuss risk-sharing in relation to farmers' wealth and credit, as one explanatory factor. This perspective is explored here in the southern Portuguese province of Alentejo, from the seventeenth to the mid-nineteenth century. Three points are made: (1) leasing and sharecropping coexisted on the same land; (2) there was no unequivocal relationship between risk sharing, on the one hand, and the contractual mode of tenancy (fixed-rent or sharecropping), on the other; and (3) relating risk-sharing, defined as a continuous variable, with social differentiation of demand for tenancies provides a rationale for a hypothetical long-term shift in contracts, from medieval sharecropping to fixed-rent tenancies with sharecrop subletting in the nineteenth century.