I. Introduction, 413. — II. A model of cash flows and the costs of cash management for business firms, 416; assumptions underlying the model, 417; optimal values of the policy parameters, 420; some properties of the solution, 423; implications for the demand for money by firms, 425; extension to allow for non-zero drift, 427.— III. The applicability of the model, 429. — Appendix, 433.

We present sufficient conditions for taxable investors to be indifferent to dividends despite tax differentials in favor of capital gains (Strong Invariance Proposition). The conditions include two ‘seemingly unrelated’ provisions of the Internal Revenue Code: (1) the limitation of interest deductions to investment income received and (2) the tax-free accumulation of wealth at the before-tax interest rate on investments in life insurance. Although we use insurance for simplicity in the proof, many tax-equivalent investment vehicles now exist, notably pension funds. Our analysis suggests that the personal income tax is approaching a consumption tax with further drift likely.

We extend the standard finance model of the firm's dividend/investment/financing decisions by allowing the firm's managers to know more than outside investors about the true state of the firm's current earnings. The extension endogenizes the dividend (and financing) announcement effects amply documented in recent research. But once trading of shares is admitted to the model along with asymmetric information, the familiar Fisherian criterion for optimal investment becomes time inconsistent: the market's belief that the firm is following the Fisher rule creates incentives to violate the rule. We show that an informationally consistent signalling equilibrium exists under asymmetric information and the trading of shares that restores the time consistency of investment policy, but leads in general to lower levels of investment than the optimum achievable under full information and/or no trading. Contractual provisions that change the information asymmetry or the possibility of profiting from it could eliminate both the time inconsistency and the inefficiency in investment policies, but these contractual provisions too are likely to involve dead-weight costs. Establishing which route or combination of routes serves in practice to maintain consistency remains for future research.

We extend the standard finance model of the firm's dividend/investment/financing decisions by allowing the firm's managers to know more than outside investors about the true state of the firm's current earnings. The extension endogenizes the dividend (and financing) announcement effects amply documented in recent research. But once trading of shares is admitted to the model along with asymmetric information, the familiar Fisherian criterion for optimal investment becomes time inconsistent: the market's belief that the firm is following the Fisher rule creates incentives to violate the rule. We show that an informationally consistent signalling equilibrium exists under asymmetric information and the trading of shares that restores the time consistency of investment policy, but leads in general to lower levels of investment than the optimum achievable under full information and/or no trading. Contractual provisions that change the information asymmetry or the possibility of profiting from it could eliminate both the time inconsistency and the inefficiency in investment policies, but these contractual provisions too are likely to involve dead‐weight costs. Establishing which route or combination of routes serves in practice to maintain consistency remains for future research.

Analytic decision rules and horizon rules are developed for the warehousing problem. A stochastic warehousing problem is defined and solved, first by backwards induction, then by means of a forward working algorithm. The influence of holding costs and discount rates on forecasting horizons is illustrated.

Using daily and monthly stock returns, the authors find no convincing evidence that Federal Reserve margin requirements have served to dampen stock market volatility. The contrary conclusion, expressed in recent papers by Gikas Hardouvelis (1988), is traced to flows in his test design. The authors do detect the expected negative relation between margin requirements and the amount of margin credit outstanding. They also confirm the recent finding by William Schwert (1988) that changes in margin requirements by the Fed have tended to follow, rather than lead, changes in market volatility.