Tribute (kharaj) as a tax on land in Islam
Tribute, as a tax on land and a tool of policy making, had a profound effect on the economy of primitive Islamic governments. The auditing and estimating of tax was different in various areas, but, until the middle of the second century, the common system was survey. Later, the division system became fashionable. Although tribute exacting increased products and capital investment, there was also an inverse relationship between tribute exacting and productivity of land.