Extensive changes in production, processing, and marketing during the last few decades have changed the chicken broiler industry from one of small, widely scattered farms to one that is large, concentrated, and efficient. More than 99 percent of all broilers produced are grown under contract and by integrated firms which vary in size of operation and complexity. About 84 percent of all production is concentrated in 10 States. Some of the other factors that contributed to these changes are costs, energy use, prices, processing, marketing, and demand.