Whereas the leadership has promoted livestock production on private farm plots, since 1968 it has placed increasingly severe restrictions on the activities of private artisans, who had originally been encouraged to expand their operations through liberal regulations issued in 1965. Aside from providing essential services, private artisans played an important role in supplying a variety of consumer goods for the population. The restrictions on artisans' activities have been based on the BKP tenet that private ownership of means of production and the use of personal property to acquire unearned income are incompatible with the socialist order and the country's new constitution. Economic activities are centrally planned and directed along lines prescribed by the BKP. The functions of planning and control are exercised by the Council of Ministers with the aid of specialized economic ministries, such as the Ministry of Finance, the Ministry of Chemical Industry and Power Generation, and the Ministry of Foreign Trade, and of various governmental committees and commissions (see ch. 8). The state banking system and, more particularly, bank credit have also served as tools for the control of enterprises and trusts. The economic management structure has been subject to frequent changes. In the spring of 1972 there were fourteen economic ministries, including five ministries exclusively concerned with branches of industry and construction. The Ministry of Agriculture and the Food Industry, as its name implies, has functioned in two major economic sectors and has also had substantial responsibilities in the field of distribution. Among the committees and commissions the most important have been the State Planning Committee, the Committee on Prices, and the Commission for Economic and Scientific-Technical Cooperation. In December 1972 the Commission on the Living Standard was created to coordinate and control the fulfillment of the national living standard program decided upon by the plenum of the Central Committee of the Bulgarian Communist Party. Attached to the Council of Ministers and chaired by a deputy minister, the commission is composed of ministers and deputy ministers, representatives of public organizations, scientists, and other members.