and was supported by the Church as well as Colombia's business leaders. The initial power-sharing agreement was effective until 1974; nonetheless, with modifications, the Liberal–Conservative bipartisan system lasted until 1990. The sixteen-year extension of the bipartisan power-sharing agreement permitted the Liberal and Conservative elites to consolidate their socioeconomic control of Colombian society, and to strengthen the military to suppress political reform and radical politics proposing alternative forms of government for Colombia. Accelerated Economic Development During the 1960s, the Colombian government effected a policy of Accelerated Economic Development (AED), the agribusiness plan of Lauchlin Currie, a Canadian-born U.S. economist who owned ranching land in Colombia. The plan promoted industrial farming that would produce great yields of agricultural and animal products for worldwide exportation, while the Colombian government would provide subsidies to large-scale private farms. The AED policy came at the expense of the small-scale family farms that only yielded food supplies for local consumption. Based on a legalistic interpretation of what constituted "efficient use" of the land, thousands of peasants were forcefully evicted from their farms and migrated to the cities, where they became part of the industrial labor pool. In 1961, the dispossession of farmland had produced 40,000 landless families and by 1969 their numbers amounted to 400,000 throughout Colombia. By 1970, the latifundio type of industrial farm (more than 50 hectares) occupied more than 77 per cent of arable land in the country. The AED policy increased the concentration of land ownership among cattle ranchers and urban industrialists, whose businesses expanded their profits as a result of reductions in the cost of labor wages after the influx of thousands of displaced peasants into the cities. During this period, most rural workers lacked basic medical care and malnutrition was almost universal, which increased the rates of preventable disease and infant mortality. History PCC and self-defense communities Communists were active throughout rural and urban Colombia in the period immediately following World War I. The Colombian Communist Party (Partido Comunista Colombiano, PCC) was formally accredited by the Comintern in 1930. The PCC began establishing "peasant leagues" in rural areas and "popular fronts" in urban areas, calling for improved living and working conditions, education, and rights for the working class. These groups began networking together to present a defensive front against the state-supported violence of large landholders. Members organized strikes, protests, seizures of land, and organized communist-controlled "self-defense communities" in southern Colombia that