M. W. Jones-Lee, A Note on a Property of the Inverse of a Bordered Matrix and Its Implication for the Theory of Portfolio Selection, The Journal of Financial and Quantitative Analysis, Vol. 9, No. 6 (Dec., 1974), pp. 1081-1087

T ESTED with regional data for the United States, the neoclassical growth model has yielded inconsistent results. Borts and Stein (1964, chapter 3) employed a simple growth model relating interregional factor movements to factor price differentials, but found little evidence of responsiveness. In a recent paper Smith (1973) found such a model consistent with the long-run factor mobility experience of states. Since a similar model was employed in both studies, the contrasting results may be ascribed to the use of inappropriate data in the test of the model of Borts and Stein, and/or inadequate model specification. They tested their model on the nonagricultural sector of each state, while Smith's model is tested on aggregate state data. Use of data on the nonagricultural sector of each state embodied the implicit assumption that capital and labor move only between states from one nonagricultural sector to another, and ignored the possibility of intersectoral factor movements. Smith avoided this potential problem by aggregating each state's output to a single sector. Thus, only interstate factor movements were relevant. In this paper, both intersectoral (within states) and interstate factor movements are considered. Factor movements affect the growth rate of a sector's capital-labor ratio, which determines the growth rate of the wage level.

Reviews the book "Self-Instructional Guide to Federal Income Taxation," by Albert J. Schneider.

Journal Article General Equilibrium with a Replenishable Natural Resource Get access Vernon L. Smith Vernon L. Smith California Institute of Technology Search for other works by this author on: Oxford Academic Google Scholar The Review of Economic Studies, Volume 41, Issue 5, December 1974, Pages 105–115, https://doi.org/10.2307/2296374 Published: 01 December 1974

Most studies of the demand for cars are designed to explain new purchases and assume that purchases are divided into net investment and replacement. Replacement is invariably identified with stock depletion, defined either as scrapping (determined by the length of life of a car) or as depreciation (determined by the decline in the price of a used car with age). Implicit in these theories is the assumption that the elasticity of substitution between the new and used car markets is rather high. This assumption is necessary to ensure that the price mechanism will induce consumers to buy new cars to make good the stock depleted by the scrapping or depreciation of used cars. Most empirical evidence indicates that this assumption is not justified and that new and used cars are poor substitutes, e.g. [1], [8] and [6]. Since the low degree of substitution between the two markets insulates new car purchases from the factors that influence the stock of used cars, stock depletion cannot explain replacement purchases of new cars. In this note an alternative approach will be suggested and its use illustrated by the case of new car sales in the US. The advantages of this approach are: (1) replacement is directly observable; (2) the assumption of perfect substitution between new and used car services is not necessary; and (3) it may help account for a series of implausible estimates of the depreciation rate that have been obtained from more orthodox models. It is generally accepted in the US automobile industry that new and used cars are bought by distinct groups. For instance, White in a recent study of the industry [6] says: New cars are not bought by a random selection of car owners but, instead, tend to be bought by a small group who buy new cars comparatively frequently and sell their used cars to the general public to hold. As an approximation, therefore, we can split buyers into two groups, those who buy their car new and those who buy it used, treating these groups as distinct. The demand of the new car buying group is primarily for replacement, since between 80 and 90 per cent of them trade-in or sell an old car when buying a new one; the average time from purchase to resale is between two and three years. This leads us to a definition of replacement as the process by which a consumer disposes of a car bought i years ago and purchases a new one. The existence of a well-developed second-hand market confirms that the replacement interval, i, is considerably shorter than the lifetime of a car, so that replacement does not equal scrapping. This replacement interval will vary between household and we shall observe a distribution of intervals, say c(i), which will determine the lag distribution generating replacement, U, from past purchases, Q; i.e.

Several titles reflecting different approaches to our subject matter were considered for the paper. An historical but somewhat pedantic approach to the teaching of investments might have been titled “Pedagogical Developments in Investments: Past, Present, and Future.” Another possibility was “Sex and the Single Investor, ” a title which probably would have attracted a larger audience. “Beat the Dealer Versus Beat the Market” might well have been an appropriate title in view of our presence here in Las Vegas and also because of recent experience in the securities markets. We finally decided on simply “A Portfolio Analysis of the Teaching of Investments, ” because this seems to better capture the essence of our viewpoint.