Efficient Estimation: The Rao-Zyskind Condition, Kruskal's Theorem and Ordinary Least Squares*

The paper emphasizes the practicability and accessibility of the necessary and sufficient condition for ordinary least squares to yield best linear unbiased estimators in several problems that are available in econometrics Two convenient equivalent alternative forms of the condition are presented It is shown that the condition is useful for analyzing different problems and is especially relevant for pedagogical purposes Several practical economic examples are presented     

An Investigation of the Effects of Specialization in Audit Workpaper Review*

Abstract. This study examines the effect of specialization at the different stages of an audit workpaper review. Auditing literature advises focusing each review level on specific kinds of errors (i.e., seniors on mechanical errors and managers on conceptual errors), rather than having seniors and managers perform successive all-encompassing reviews. However, surveys of review practice suggest that all-encompassing reviews are common. To determine whether specialization at different levels of review improves reviewers' overall effectiveness, this study has 35 managers and 39 seniors actually perform a review of a realistic set of workpapers. Half the subjects performed specialized reviews, whereas the other half performed all-encompassing reviews. Overall accuracy rates in our study are consistent with prior research. In addition, the combined reviews of seniors and managers are more effective than those of either seniors or managers separately, demonstrating the benefits of hierarchical review. However, specialized review leads reviewers to be significantly less accurate than reviewers performing all-encompassing reviews. The results suggest specialization will not automatically improve review effectiveness, and that accounting firms may need to re-evaluate their review guidance and professional training on workpaper reviews.     

The Impacts of the California Beverage Container Recycling and Litter Reduction Act on Consumers

In late 1987 the California Beverage Container Recycling and Litter Reduction Act went into effect. Like mandatory beverage deposit legislation in other states, this Act is designed to promote returns through the payment of a redemption value. However, unlike traditional legislation, the Act attempts to promote recycling with lower redemption values and more state intervention. This paper presents a methodology for analyzing the impacts of beverage container recycling legislation on consumers. Applying this methodology to California, it is found that the Act will significantly reduce beverage container solid waste and litter, but the net benefits of the Act depend critically on consumers' valuations of intangible benefits.     

Sell‐Side Analyst Research and Stock Comovement

We document that a stock's price around a recommendation or forecast covaries with prices of other stocks the issuing analyst covers. The effect of shared analyst coverage on stock price comovement extends beyond analyst activity days. A stock's daily returns covary with the returns of other stocks with which it shares analyst coverage. These links between stock price comovement and shared analyst coverage are consistent with the coverage‐specific information we find in earnings forecasts; analysts who cover both stocks in a pair expect future earnings of the stocks to be more highly correlated than do analysts who cover only one stock from the pair. Collectively, our evidence indicates that analyst research produces coverage‐specific spillovers that raise price comovement among stocks that share analyst coverage. The strength of these spillovers is comparable to spillovers from broad industry and market information in analyst research.     

Tightening the Fiscal and Monetary Controls

The Medium-Term Financial Strategy (MTFS) is a new departure in post-war policy-making. As David Smith's Briefing Paper shows the ideas behind it are well rooted in historical experience, but nevertheless it was inevitable that there would be a major element of trial and error in the early years of its use. The experience of 1980-81 however has produced some alarming results. The monetary limits have been drastically exceeded and the PSBR is likely to be far above the original target. There are two possible explanations. Either the control system is gravely defective or the government has deliberately followed the kind of short-term discretionary policies (and has indulged in the kind of ad hoc interventionism) which the strategy was expressly designed to avoid. We believe that both explanations are true. It is also probable that they reinforced each other. The first year of the strategy was likely to be the year of greatest strain. It involved a highly ambitious attempt to reduce inflation at a time when cost pressures from wages and higher energy prices were particularly strong. The strains rapidly revealed the defects in the control system. Since the government was alarmed at the short-term consequences of its policies, it chose to make a virtue of necessity and in effect suspended its commitment to the control of sterling M3. It is possible to look back at 1980 and to say that, in the event, the government's loss of control over its policies was justified as statesmanlike flexibility. But there always appear to be good reasons for sacrificing long-term objectives for short-term expediency. The MTFS was intended to avoid the chronic tendency to accept the easy option. It is essential that in 1981 the commitment to the MTFS should be re-established and that it should be reinforced, as appears to be necessary, by a system of indicators and controls to ensure that the errors of 1980 are not repeated. Otherwise there is a serious risk that the hard-won gains in the fight against inflation will be lost in the economic upturn. In the first part of this Viewpoint we examine what happened to fiscal and monetary policy in 1980 and discuss the general lines that policy should follow in 1981-82. We conclude that in order to get fiscal policy back on course the authorities should aim for a PSBR of £10 bn in 1981-82. In the second part we discuss in more detail the reasons why monetary policy went so badly astray in 1980, focusing particularly on the role of the Bank of England. We argue that just as ‘dirty floating’ (i.e. the pursuit of exchange rate objectives) may threaten the monetary targets, so ‘dirty monetarism’ (i.e. the pursuit of interest rate objectives) may prove an even greater threat. We conclude that the discretionary activities of the Bank of England contributed to the excessive monetary growth in 1980, and that it is necessary to ensure that in future the Bank should conduct its policy on a non-discretionary basis.     

PRODUCT IMPROVEMENT AND TECHNOLOGICAL TYING IN A WINNER‐TAKE‐ALL MARKET*

In a winner‐take‐all duopoly for systems in which firms invest to improve their products, a vertically integrated monopoly supplier of an essential system component may have an incentive to advantage itself by technological tying. If the vertically integrated firm is prevented from technologically tying, there is an equilibrium in which the more efficient firm invests and serves the entire market. However, another equilibrium may exist in which the less efficient firm wins the market. Technological tying enables a vertically integrated firm to foreclose its rival. The welfare implications of technological tying are ambiguous and depend on equilibrium selection.