Experts have clashed here over how to respond to a global food crisis that has sparked riots, toppled governments and threatened the lives of millions. The disagreement over agricultural policies needed to address world hunger underscored a dilemma at the heart of the debate: that urban populations demand cheap food in order to survive and poor farmers need higher food prices in order to make a living. \"Food prices are literally a matter of life and death, especially for the poor who spend up to 80 or 90 percent of their income on food,\" Angel Gurria, the secretary-general of the Organization for Economic Cooperation and Development (OECD), told a panel of experts at the International Economic Forum of the Americas. \"The problem is that high prices may be here to stay,\" Gurria said. Agricultural experts have argued that food shortages were a catalyst in uprisings in the Middle East. In August, Russia banned wheat exports, thereby canceling 600,000 orders from Egypt, where people spend 40 percent of their income on food. Food prices spiked shortly thereafter, and riots ensued. Gurria cautioned governments against \"panicking and exacerbating\" prices by slapping export bans on food, saying export restrictions caused \"the spike in the hike.\" \"Governments need to roll back measures that distort production and trade and that prevent blood from flowing from surplus to deficit areas where it is needed. Let it flow. Let the market determine where to go.\" \"Farmers in the developed world have the know-how and the technologies and the business environment to enable them to expand production.\" But the market approach has nonetheless failed to help poorer farmers in the rest of the world, others argued. The OECD economist said developing nations needed to improve infrastructure and ensure good governance in order for private and public sectors in developed countries to invest. \"In India for example, 30 to 40 percent of production is lost because of storage facilities, infrastructure facilities, transportation facilities and ports. One has to qualify this as a very great tragedy,\" he said. John Baffes, a World Bank economist, said unpredictable weather patterns, higher energy costs, a weak dollar, and an increase in demand for food for biofuels, all helped create the \"perfect storm\" which led to hikes in food prices over the last decade. Baffes also warned against export restrictions as a way to manage food shortages. But one of France\'s most respected agronomists, Marcel Mazoyer, took a swipe at market forces as the sole way to solve the food crisis. \"Trying to maximize profit in the short term creates so much poverty that it strangles an emerging economy,\" said Mazoyer, professor emeritus at the Institut National Agronomique de Paris-Grignon. Mazoyer unleashed staggering figures to the panel of development experts, multilateral officials and academics attending the Montreal conference. \"There are three billion people who suffer from significant food shortages, two billion who suffer from illness and disease related to malnutrition, and in 2010, 925 million who go hungry every day.\" He said global poverty was largely a problem suffered among the rural poor. \"Poverty, undernourishment and malnutrition are massively rural.\" Very few of the world\'s 1.4 billion poor farmers have tractors, he pointed out. Most are forced to farm with outdated tools such as hoes, spades, digger sticks and machetes. But Mazoyer said historically low food prices were the problem. \"The major cause of insufficient income for hundreds of millions of under-equipped and unproductive farmers around the world has been the decades of low food prices.\" \"When international prices are low it\'s impossible to survive, and when food prices are higher, they are in any case insufficient for an African farmer.\" Mazoyer said food production needs to increase by 30 percent in order to meet consumption needs. \"We need to massively invest in equipment and pay farmers the price they need to make a living, not the market price,\" he urged.