TY - JOUR AU - Caballero,Ricardo J. AU - Lyons,Richard K. TI - The Role of External Economies in U.S. Manufacturing JF - National Bureau of Economic Research Working Paper Series VL - No. 3033 PY - 1989 Y2 - July 1989 UR - http://www.nber.org/papers/w3033 L1 - http://www.nber.org/papers/w3033.pdf N1 - Author contact info: Ricardo J. Caballero MIT Department of Economics Room E52-373a Cambridge, MA 02142-1347 Tel: 617/253-0489 Fax: 617/253-6915 E-Mail: caball@mit.edu Richard K. Lyons 460 Michigan Ave Berkeley, CA 94707 Tel: 510-642-1059 Fax: 510-642-4700 E-Mail: lyons@haas.berkeley.edu AB - This paper develops a method for joint estimation of both the degree of internal returns to scale and the extent of external economies. We apply the method in estimating returns to scale indexes for U.S. manufacturing industries at the two-digit level. Overall, we find that only three of the twenty industry categories show any evidence of internal increasing returns: (1) Primary Metals, (2) Electrical Machinery, and (3) Paper Products. More striking, however, is the very strong evidence of the existence of external economies, where external is defined as external to a given two-digit industry and internal to the U.S.. According to our preferred estimates, if all manufacturing industries simultaneously raise their inputs by 10%, aggregate manufacturing production rises by 13%, of which about 5% is due to external economies. Thus, when an industry increases its inputs in isolation by 10%, its output rises by no more than 8%. ER -