Historians generally agree that Japan's ritsuryo state structure reached its apogee during the Nara period and that only in the last half of the period, particularly after 740, were its foundations undermined by changing social and economic conditions. The people of Nara Japan were classified by law as commoners or slaves. The state's financial arrangements were devised in accordance with the principle that the state should collect enough taxes in kind to meet its operating costs. Taxes paid by farmers who had received land allotments were of two types: a portion of the rice produced and a portion of the articles made. Most exchange in Nara times was associated with the government's collection of goods and services from outlying areas. After 730, legal enactments reflect a fundamental change of policy. Particularly significant were the state's recognition of private possession of rice land in perpetuity, the granting of legal status to vagrants, and changes in the state-loan system.