Chronic underinvestment in agriculture over the last 20 years combined with trade liberalisation has trapped many developing countries in a vicious cycle of low agricultural productivity and dependence on cheap food imports. The one exacerbates the other as local farmers struggle, and fail, to get a decent price for their produce in competition with imports, which have often benefited from government subsidies. Local farming goes into steep decline leading to migration to the cities. This is a serious market failure. Faced with large hungry (and often jobless) urban populations, government policy is driven by the need to keep food cheap at all costs or risk political instability.