remained high. As of 2004, 98% of all U.S. farms were family-owned and -operated. Most meat and dairy products are now produced on large farms with single-species buildings or open-air pens. Due to their increased efficiency, CAFOs provide a source of low cost animal products: meat, milk and eggs. CAFOs may also stimulate local economies through increased employment and use of local materials in their production. The development of modern animal agriculture has increased the efficiency of raising meat and dairy products. Improvements in animal breeding, mechanical innovations, and the introduction of specially formulated feeds (as well as animal pharmaceuticals) have contributed to the decrease in cost of animal products to consumers. The development of new technologies has also helped CAFO owners reduce production cost and increase business profits with less resources consumption. The growth of CAFOs has corresponded with an increase in the consumption of animal products in the United States. According to author Christopher L. Delgado, "milk production has doubled, meat production has tripled, and egg production has increased fourfold since 1960" in the United States. Along with the noted benefits, there are also criticisms regarding CAFOs' impact on the economy. Many farmers in the United States find that it is difficult to earn a high income due to the low market prices of animal products. Such market factors often lead to low profit margins for production methods and a competitive disadvantage against CAFOs. Alternative animal production methods, like "free range" or "family farming" operations are losing their ability to compete, though they present few of the environmental and health risks associated with CAFOs. Negative production externalities Critics have long argued that the "retail prices of industrial meat, dairy, and egg products omit immense impacts on human health, the environment, and other shared public assets." The negative production externalities of CAFOs have been described as including "massive waste amounts with the potential to heat up the atmosphere, foul fisheries, pollute drinking water, spread disease, contaminate soils, and damage recreational areas" that are not reflected in the price of the meat product. Environmentalists contend that "citizens ultimately foot the bill with hundreds of billions of dollars in taxpayer subsidies, medical expenses, insurance premiums, declining property values, and mounting cleanup costs." Some economists agree that CAFOs "operate on an inefficient scale." It has been argued, for instance, that "diminishing returns to scale quickly lead to costs of animal confinement that