We can use price elasticities to determine whether markets are in fact perfectly competitive (or at least close to perfectly competitive). The following table summarizes estimated price elasticities for US farmers.

\fCrop Number Individual farm's of farms elasticity of demand Apples 41,187 -8,649 Sweet cherries 14,078 -10,840 Grapes 24,082 -3.927 Peaches 23,121 -5,813 Pears 13.244 -21,711 Plums/prunes 11,156 -7,047 Snap beans 12,260 -11.544 Sweet corn 29,260 -31,353 Cucumber 9.935 -5,653 Lettuce 2.452 -809 Dry onions 3,516 -2.074 Peas 8,204 -5,579 Tomatoes 17,280 -2,766 Source: Carbon and Perill (1899)