Experiments, Investor expectation, Abnormal performance index, Residual analysis

Since the publication of the work of Modigliani and Miller (MM) in the late 1950s there has been a recurrent controversy in the finance and economics literature about the interdependence of investment and financial variables. The arguments are too well known to recount at any length here. Basically MM would argue that in perfect capital markets, investment is, and should be independent of financing (which we will identify, as they would, with financial variables like dividends and new debt). The opposing view would argue that capital markets are sufficiently imperfect that the firm must consider financing in its investment decision. At least some of the proponents of this other view would argue that the firm must raise funds and allocate these scarce funds between investment and dividends. This view, then, holds that the firm's investment, dividend, and financing decisions are interdependent and must be studied in the context of a simultaneous equation model. There have been many articles discussing the MM position and many attempts to test it empirically. The first to focus directly on the question of interest here was done by Dhrymes and Kurz [1] in 1967. We will attempt to show that, despite several later studies, Dhrymes and Kurz were correct in their assertion that the investment and financing decisions are made simultaneously and must be studied in the context of a simultaneous equation model. To set the stage for our study we shall review the Dhrymes-Kurz study and subsequent related studies and show that each contained some error that affected their results.

The widespread notion that dollar-cost averaging can help an investor minimize the risk of investing all of one's capital in the market at an inappropriate time is aptly stated by Malkiel [4, p. 242]:Periodic investments of equal dollar amounts in common stocks can substantially reduce (but not avoid) the risks of equity investment by insuring that the entire portfolio of stocks will not be purchased at temporarily inflated prices. The investor who makes equal dollar investments will buy fewer shares when prices are high and more shares when prices are low.

In the September 1975 issue of this Journal Ben Branch works out in detail an “optimal” strategy for an investor seeking to purchase or sell a security. The suggested strategy involves placing limit orders at specified prices and then waiting for the order to be filled. Hypothetical calculations indicate the magnitude of savings possible through use of the strategy. Ben Branch apparently accepts the standard random walk model and develops his theory around it. If one believes that the value of a stock is a constant and that prices fluctuate randomly, the treatment seems correct.

In a Walrasian economy, differences among agents in their attitudes towards risk do not constitute an inducement to trade. This is an outcome of the assumption of existence of a complete system of markets in contingent commodities.1 The assumption is, however, empirically unjustified. It is this observation that underlies the implicit theory of employment introduced by Baily (1974) and Azariadis (1975) and further elaborated by Baily (1975), Sargent (1975), Feldstein (1976), Negishi (1976) and Varian (1976). The assumptions and conclusions of the implicit contract theory can be briefly summarized as follows: It is assumed that a firm has a certain pool of workers associated with it and faces an uncertain price for its output. It is further postulated that the firm's objective function is the expected value of its profits, while workers desire to maximize the expected utility of their income, the latter characterized by risk aversion. The firm chooses the employment contract which maximizes its expected profit subject to the constraint that it provide the workers with a minimum of expected utility. The latter is supposed to reflect the opportunities open for workers elsewhere in the economy. Under these assumptions it can be demonstrated that the optimal contract involves full employment of the firm's labour pool at all states of nature, and a constant wage rate-i.e. a wage rate independent of the contingency realized. The above formulation involves a number of conceptual and empirical problems: It is assumed there is unanimity concerning the probability of occurrence of the various states of nature. Furthermore, not only are workers identical, but firms know the exact form of their utility function. The argument depends crucially on the risk neutrality of firms. In the absence of markets for contingent securities this assumption can only be justified in the very special case of perfect negative correlation between the profits of different firms. Otherwise one has to rely either on the superiority of firms vis-a-vis workers concerning the accessibility to capital markets, or in some Knightian distinction between the innate risk neutrality of entrepreneurs and risk aversion of workers. Workers are assumed to have an indirect utility function separable in income and prices. If this is not the case, even though firms behave parametrically with respect to the prices of goods, they must take into account portfolio-theoretic considerations on the part of workers. Since the only constraint faced by a firm is that the expected utility provided by the contract it offers be greater than or equal to some competitively determined level, it is implicitly assumed that workers cannot abandon the firm after the state of nature has been realized. Equivalently, the costs of movement for workers past the initial contracting period are assumed to be infinitely high. For otherwise, the constraints faced by a firm would take the form of a minimum wage to be paid at each state of nature. In the extreme case of costless labour mobility, this implies that firms are wage takers in the labour market.

I. Introduction, 465.—II. The model and results, 466.—III. Conclusion, 469.

AbstractIt is well known that the returns on various betting opportunities at a racetrack are determined by a competitive bidding of the bettors in a natural environment of their decision making. In this paper, two simple bets of unknown but identical winning probabilities are identified. An analysis of 1,089 observations shows the data are consistent with the hypothesis that both bets are identically priced, an implication of an efficient speculative market.

Recent work by Richard Roll has challenged the worth of portfolio performance measures based on the capital asset pricing model. This paper demonstrates that Roll's conclusions are due to his focusing on a ‘truly’ ex-ante efficient index. Using a choice and information theoretic framework, we show that an appropriate index is efficient relative to the probabilities assessed by the ‘market’. Residual analyses and portfolio performance tests, using such an index, yield meaningful results for a wide class of information structures. Roll's primary criticisms, however, relate to tests of the asset pricing model itself. We argue that these criticisms are vastly overstated.