Government interventions in the agricultural economy influence the quantities produced and price of food. A number of different instruments are used to incentivize farmers to grow crops and buffer them through difficult economic or weather cycles, including price supports, supply controls, deficiency payments, direct payments, insurance, and demand expansion. The United States farm bill specifies the type of policy instruments that will be funded in a given cycle and at what cost. Subsidies to farming interests, determined primarily by the farm, are expected to cost $223 billion over the 10-year period from 2013 to 2022, according to the Congressional Research Service (CRS). Crop insurance is the most expensive of the federal farm subsidies, followed by conservation policies and commodity supports. Representatives and senators from states that receive the lion's share of farm subsidies often dominate the committees on agriculture in the House and Senate. Agricultural economics plays an increasingly larger role in the understanding of both domestic and global food trade policy decisions.