The following calculator shows the supply curve for sedans in an imaginary market. For simplicity, assume that all sedans are identical and sell for the same price. Two factors that affect the supply of sedans are the level of technical knowledge—in this case, the speed with which manufacturing robots can fasten bolts, or robot speed—and the wage rate that auto manufacturers must pay their employees. Initially, the graph shows the supply curve when robots can fasten 2,500 bolts per hour and autoworkers earn $25 per hour.