The Impact of Option Introduction on Stock Return Variances: The Role of Bid-Ask Spreads, Return Autocorrelations, and Intrinsic Variances

The purpose of this paper is to examine changes in stock return variances following option introduction. The sample consists of National Market System stocks and employs both transaction returns and returns based on bid and ask quotes. Variances are decomposed into portions attributable to bid-ask spreads, return autocorrelations, and intrinsic variances. Spreads play a negligible role in explaining variance changes. A generally positive component to short-term autocorrelations falls following option introduction, increasing variances over short holding periods. Intrinsic variances fall prior to the October 1987 crash, but do not change after the crash with option introduction.     

Focusing the fuzzy front–end in new product development

Effectively managing the 'upfront or fuzzy front–end' (FFE) of the product development process is one of the most important, difficult challenges facing innovation managers. In this paper, we define the FFE as the period between when an opportunity is first considered and when an idea is judged ready for development. We classify the outcomes of the FFE into product definition, time, and people dimensions. We suggest several strategies to manage the FFE by assigning a FFE manager or team; by providing organizational support for FFE activities; by understanding the sources of FFE ambiguity; by building an information system; and by developing relationships with supporters, partners, and alliances.     

Product Development Strategy and Organizational Learning: A Tale of Two PC Makers

The personal computer (PC) marketplace in the US presents a dizzying array of component suppliers and products. No single firm dominates the industry with a complete package of hardware and software components. Although one company's operating systems and general-purpose applications are installed on most PCs in the US, the other system components—processors, memory, storage devices, display adapters, monitors, specialized applications, and so on—come from any number of sources. David T. Methe, Ryoko Toyama, and Junichiro Miyabe point out that the PC industry in Japan also exhibits this decentralized nature. However, they also note that despite the decentralized network structure of the Japanese PC industry, one company—NEC—was able to achieve a dominant market share. To provide insight into the key issues involved in the management of complex technology, they contrast NEC's strategic approach to product development and organizational learning with the approaches taken by Fujitsu—the firm that placed a distant second in this market. Despite matching NEC in terms of technological capabilities, financial resources, and managerial talent, Fujitsu never managed to threaten NEC's dominance of the PC market in Japan. Fujitsu continually emphasized technological leadership, even at the expense of protecting its installed base. Poor coordination of resources and product development efforts resulted in incompatibilities among Fujitsu's various products, and the company failed to foster close relationships with suppliers of such key technologies as software and peripherals. NEC's PCs did not enjoy the advantages of first-to-market status or technological leadership. Instead, NEC achieved market dominance by finding the combination of product technologies that met the needs of the greatest number of consumers. Throughout almost 20 years of competition in the PC industry, NEC successfully maintained consistency and backward compatibility across its product lines. NEC also recognized the importance of third-party software developers, and carefully cultivated relations with these firms as a source of competitive advantage. In other words, NEC struck the right balance between three key factors: technological innovation, motivation of third-party developers of software and peripherals, and service to its installed base of customers.     

Information Disclosure to Employees and Rational Expectations: a Game-Theoretical Perspective: a Comment

In this comment we identify the key features of the Frantz and Walker (1997) game theoretic model that drive the non-disclosure equilibrium result in their paper. We argue that, although technically correct, their model fails to capture certain aspects of real-world wage bargaining that will be important in determining optimal disclosure strategies in practice. However, Frantz and Walker's paper illustrates the potential of analytical techniques to contribute to the employee disclosure debate.     

THE RETURNS TO ENDOGENOUS HUMAN CAPITAL IN PAKISTAN'S RURAL WAGE LABOUR MARKET

This paper estimates the private returns to human capital in Pakistani rural labour markets. The rich data used permit inclusion of several dimensions of human capital and control for endogeneity resulting from investment in human capital. The results suggest that, without data on determinants of human capital, it would not be possible to disentangle the separate effect of each dimension of human capital on wage differentials nor to distinguish human capital explanations for wage differentials from signalling and credentialist models. With control for endogeneity of human capital and selectivity into wage employment, cognitive achievement, but not schooling attainment separate from cognitive achievement nor long-run health status, affects wage differentials.     

Quality Competition and Social Welfare in Markets with Partial Coverage: New Results*

We use a vertical product differentiation model under partial market coverage to study the social welfare optimum and duopoly equilibrium when convex costs of quality provision are either fixed or variable in terms of production. We show the following new results. First, under fixed costs, the social planner charges a uniform price for the single variant that just covers costs of quality provision. Like the duopoly equilibrium, this socially optimal pricing entails a partially uncovered market, but a smaller share of the market is served compared with the duopoly equilibrium. Second, for the variable cost case, it is socially optimal to provide both high‐ and low‐quality variants, but market shares need not be equal. This differs from the result in fully covered markets. Third, in the duopoly equilibrium, the quality spread is too wide under variable costs relative to the social optimum. Under fixed costs, the duopoly produces two variants, but quality is too low relative to the social optimum, which has only one variant.     

Boundedly complete families which are not complete

Summary Completeness of a family of probability distributions implies its bounded completeness but not conversely. An example of a family which is boundedly complete but not complete was presented by Lehmann and Scheffe [5]. This appears to be the only such example quoted in the statistical literature. The purpose of this note is to provide further examples of this type. It is shown that any given family of power series distributions can be used to construct a class containing infinitely many boundedly complete, but not complete, families. Furthermore, it is shown that the family of continuous distributions , is boundedly complete, but not complete, whereU denotes the uniform distribution on [a, b] and {P _ϑ,ϑ ∈ IR}, is a translation family generated by a distributionP ₀ with mean value zero, which is continuous with respect to the Lebesgue measure.