Technological change and product life cycle concepts can be used to explain the concentration of cotton textile production in Southeastern New England during the industry's period of rapid innovation in machinery and machine tool design. Boston was the center for an agglomeration of high technology industries that were attracted by each other and the local resource pool of skilled mechanics and entrepreneurs. The movement of the textile industry to the Southeast, which took place after 1880, is linked to technological change in the product cycle that substituted unskilled labor for skilled labor and high technology inputs. The phrase "Yankee ingenuity " has be-come a part of the English language. If New England no longer holds all the good mechanics in the United States, there was a time when she came so near it that the term "New England mechanic " had a very definite meaning over the whole country [Roe, 1916, p. 109]. The nineteenth century industrialization process in the United States was quite unbalanced geographically. The major manufac-turing industries were highly concentrated in New England and the Middle Atlantic states, while the South lagged far behind. The textile industry is the example most often used to illustrate this imbalance. It was centered in New England during the nineteenth century but moved "belatedly " to the Southeast in the twentieth century. Most histories of the industry cite abundant water power and merchant capital as reasons for the original New England location, and the low wages and less restrictive labor laws in the South are said to explain the relocation. This paper argues that the textile industry became highly concentrated in Eastern Massachusetts and Rhode Island during the nineteenth century because of localization economies re-sulting from close proximity to the source of technological change in the industry. Textile firms, machinery builders, and entrepreneurs formed an agglomeration of skills and other resources which made firms more *I wish to thank Roger Bolton, John R. Meyer, and Christine Hekman for ideas and criticism, and a referee of this Journal for valuable suggestions. Work on this paper

The framework for urban spatial models as developed in the last twenty years contains two main features: access and bid rent. In a recent article in this Review, William Wheaton (1977b) done serious damage to this framework by concluding that the long-run spatial equilibrium theory derived from bid rent contributes little to the explanation of American location-income patterns (p. 631). He finds that the theory developed by William Alonso, Richard Muth, and others produces a very weak tendency for middleand upper-income families to live at a greater distance than poor families from the central business district (CBD). The purpose of this note is to argue that the Alonso-Muth theory is an important tool in understanding urban structure if account is taken of one previously ignored factor-that the labor force participation of married women varies dramatically and inversely with the income of their husbands. Middleand lowerincome households have more of their members in the labor force, and this pulls these groups closer to the CBD. Muth and Wheaton have noted that there is only a weak relationship empirically between median family income and distance from the CBD. Muth (p. 263) found that income did not increase with distance on the South Side of Chicago when the age of the housing stock was included in the regression. This gives more support to the filtering model of urban structure than to Muth's analysis.' Wheaton (1977b) finds that bid-rent schedules decrease very little in slope as income increases, thus producing a very weak tendency for higher income households to live farther out. The models underlying the analyses of Wheaton and Muth rely on the simplifying assumption of a one-worker household. A caveat is usually stated regarding the effect of multiple-worker households (see Muth, p. 41; Wheaton, 1977a, p. 206). Others have looked at the two-worker household but have not made the connection between working wives and husbands' incomes (see Walter Oi; Michelle White; Oded Hochman and Haim Ofek), although this connection was noted some time ago in the labor economics literature (see Glen Cain). The fact that wives' labor supply is a major factor in the urban labor force is illustrated by Table 1. The participation rates of married women, husband present, decline with husband's income in almost every category, except the numerically unimportant case of husbands who earned under $3,000. In most categories the rates at the $3,000-6,000 level are double or more the rates for the over $15,000 level. However, participation rates also differ quite a bit by age, both because of life cycle effects such as schooling and childbearing, and because of the pronounced time trend of wives' participation, shown in Table 2. Younger labor force members have made different decisions regarding careers and investment in human capital, which argues for treating them separately from older workers. The participation of married women in the labor force been increasing steadily for about a century. This coincides with Wheaton's observation on the timing of the movement of upper-income groups to the suburbs, which, he says, has been evolving gradually ever since the streetcar suburbs of the late nineteenth century (1977b, p. 620). Thus the changing characteristics of the labor force have accompanied the changing location of households by income. *Boston College. I received a great deal of helpful criticism on this paper from Christine Hekman, Marvin Kraus, John Meyer, and Joseph Quinn. Financial support for this research was provided by the HarvardM.I.T. Joint Center for Urban Studies. 'I am indebted to John Meyer for valuable help in pointing out some of the implications of Muth's empirical results.