The investment effects of five major tax proposals and the Tax Reform Act of 1986 1 are examined by combining an econometrically estimated investment function with the cost of capital associated with each proposal. All the tax proposals increase the cost of capital and amplify current decreases in agricultural capital disinvestment. The proposals are bounded above by the Kemp-Kasten plan which reduces net investment by about $190 million and below by the House plan which accounts for yearly declines in excess of $320 million. In addition, the repeal of the investment tax credit is responsible for about 98 percent of the decline in net investment under the Tax Reform Act of 1986.