John B. Long

Real Business Cycles

In this paper we demonstrate how certain very ordinary economic principles lead maximizing individuals to choose consumption-production plans that display many of the characteristics commonly associated with business cycles. Our explanation is entirely consistent with (i) rational expectations, (ii) complete current information, (iii) stable preferences, (iv) no technological change, (v) no long-lived commodities, (vi) no frictions or adjustment costs, (vii) no government, (viii) no money, and (ix) no serial dependence in the stochastic elements of the environment. We also provide a completely worked out example of the type of artificial economy we have in mind. The time-series properties of the example exhibit some major features of observed business cycles. Although this type of model may not be capable of explaining all of the regularities in actual business cycles, we believe that it provides a useful, well-defined benchmark for assessing the relative importance of factors (e.g., monetary disturbances) that we have deliberately ignored.

Efficient portfolio choice with differential taxation of dividends and capital gains

Abstract A simple, necessary and sufficient condition is derived under which portfolios that are mean-variance efficient on a before-tax basis are also efficient on an after-tax basis and vice-versa. Under this condition and the hypothesis that investors demand after-tax efficient portfolios, the ‘no-tax’ form of the Capital Asset Pricing Model provides an accurate description of equilibrium asset returns even though investors in the economy may be subject to a wide variety of tax rates on dividends and capital gains. Evidence reported by Black and Scholes (1974), however, makes the condition for equivalence of before and after-tax efficiency empirically implausible. The paper thus concludes with a characterization of some essential differences between before and after-tax efficient portfolios and of the after-tax efficiency losses associated with before-tax efficient portfolios. The relation of these results to the issue of corporate dividend policy choices is also discussed.

Implementing Fischer Black's Simple Discounting Rule

Corporate managers typically estimate the value of capital projects by discounting the project’s expected future net cash flows at the cost of capital. The capital asset pricing model (CAPM) is generally used to estimate that cost. But, as anyone who has worked on the finance or business development staff of a public company can attest, there are major challenges in applying the CAPM, including largely unresolved questions about what constitutes the “market portfolio,” how to estimate market risk premiums, and how to estimate the betas of projects. In a short article published in Financial Management in 1988, Fischer Black proposed a valuation “discounting rule” that avoids all these problems - one that involves discounting a relatively certain (as opposed to an expected or average) level of operating cash flows at the risk-free rate. But Black’s article does not address the question of how to calculate these “certainty equivalent” or “conditional” cash flows. In this article, the authors propose a way of implementing Black’s rule that involves estimating the “conditional” cash flows in a three-step procedure: • Find a benchmark security that correlates with the project’s cash flows; • Estimate the percentiles of the distribution in which the benchmark return equals the risk-free rate over different investment horizons; • Use information from corporate managers to assess the cash flows that define the same percentiles in the cash flow distributions. As the authors point out, the virtue of Black’s rule is that it shifts the focus of the analyst away from the assessment of discount factors and puts it squarely on the more challenging, and arguably more relevant, problem of estimating the project’s cash flows.