Chapter 51 Efficiency and Equity Effects of Land Markets It is widely believed that land markets including both land sales and tenancy markets are neither efficient nor conducive to social equity. It is often argued that tenants particularly share tenants do not have proper incentives to work and invest partly because of the disincentive effects of output sharing and partly because of the tenure insecurity. It is also widely accepted that land sales transactions tend to exacerbate the social equity and rural poverty by facilitating the concentration of land ownership by hands of a few wealthy landlords. Based on these presumptions land reform programs have been implemented in a number of developing countries. This article critically reviews these presumptions both theoretically and empirically. Firstly we identify why land tenancy transaction is more common than land sales transactions and why share tenancy is more common than leasehold tenancy. Secondly we critically review the theories of share tenancy tenure security and adjustment costs of farm size. Thirdly we empirically review the efficiency and equity effects of land markets as well as the impacts of conventional land reform programs. It has become clear from the literature review that land reform polices have generally failed to improve land use efficiency and social equity. It is also found that tenancy contracts including share tenancy are generally efficient and conducive to social justice. In conclusion we propose to encourage tenancy transactions in general and share tenancy in particular.