Improved forecasting of autoregressive series by weighted least squares approximate REML estimation

Restricted maximum likelihood (REML) estimation has recently been shown to provide less biased estimates in autoregressive series. A simple weighted least squares approximate REML procedure has been developed that is particularly useful for vector autoregressive processes. Here, we compare the forecasts of such processes using both the standard ordinary least squares (OLS) estimates and the new approximate REML estimates. Forecasts based on the approximate REML estimates are found to provide a significant improvement over those obtained using the standard OLS estimates.     

Risk sharing and retrading in incomplete markets

At a competitive equilibrium of an incomplete-markets economy agents’ marginal valuations for the tradable assets are equalized ex-ante. We characterize the finest partition of the state space conditional on which this equality holds for any economy. This leads naturally to a necessary and sufficient condition on information that would induce agents to retrade, if such information was to become publicly available after the initial round of trade.     

Information Revelation and Market Incompleteness

This paper introduces a theory of market incompleteness based on the information transmission role of prices and its adverse impact on the provision of insurance in financial markets. We analyse a simple security design model in which the number and payoff of securities are endogenous. Agents have rational expectations and differ in information, endowments, and attitudes toward risk. When markets are incomplete, equilibrium prices are typically partially revealing, while full relevation is attained with complete markets. The optimality of complete or incomplete markets depends on whether the adverse selection effect (the unwillingness of agents to trade risks when they are informationally disadvantaged) is stronger or weaker than the Hirshleifer effect (the impossibility of trading risks that have already been resolved), as new securities are issued and prices reveal more information. When the Hirshleifer effect dominates, an incomplete set of securities is preferred by all agents, and generates a higher volume of trade.     

Speculative securities

Summary. A speculative security is an asset whose payoff depends in part on a random shock uncorrelated with economic fundamentals (a sunspot) about which some traders have superior information. In this paper we show that agents may find it desirable to trade such a security in spite of the fact that it is a poorer hedge against their endowment risks at the time of trade, and has an associated adverse selection cost. In the specific institutional setting of innovation of futures contracts, we show that a futures exchange may not have an incentive to introduce a speculative security even when all traders favor it. Received: July 19, 1998; revised version: August 31, 1998     

History of offshoring knowledge services

The offshoring of knowledge services has become the stuff of newspaper headlines and U.S. presidential debates. Here, we view the antecedents of the current state of affairs. In the 1980s services offshoring was a trivial portion of the economy, but the seeds of today's situation were planted then. A combination of U.S. government neglect, foreign government activism, a culture change among business people concerning service processes, technological advances, and cultural relationships among countries have created the specific services offshoring configuration of today.     

A stochastic cellular automata model of innovation diffusion

A stochastic cellular automata model of new product diffusion is proposed. It is found that the growth for a given market potential can be determined by a parameter that quantifies chance preferences of individuals for the product and can be estimated from field surveys. It is also found that the “takeover time” in a given seed region is almost independent of the number of innovators. The results suggest possible strategies for the successful introduction of a new product.     

Up to code: does your company's conduct meet world-class standards?

Codes of conduct have long been a feature of corporate life. Today, they are arguably a legal necessity--at least for public companies with a presence in the United States. But the issue goes beyond U.S. legal and regulatory requirements. Sparked by corruption and excess of various types, dozens of industry, government, investor, and multisector groups worldwide have proposed codes and guidelines to govern corporate behavior. These initiatives reflect an increasingly global debate on the nature of corporate legitimacy. Given the legal, organizational, reputational, and strategic considerations, few companies will want to be without a code. But what should it say? Apart from a handful of essentials spelled out in Sarbanes-Oxley regulations and NYSE rules, authoritative guidance is sorely lacking. In search of some reference points for managers, the authors undertook a systematic analysis of a select group of codes. In this article, they present their findings in the form of a "codex," a reference source on code content. The Global Business Standards Codex contains a set of overarching principles as well as a set of conduct standards for putting those principles into practice. The GBS Codex is not intended to be adopted as is, but is meant to be used as a benchmark by those wishing to create their own world-class code. The provisions of the codex must be customized to a company's specific business and situation; individual companies' codes will include their own distinctive elements as well. What the codex provides is a starting point grounded in ethical fundamentals and aligned with an emerging global consensus on basic standards of corporate behavior.     

The Performance,Asset Allocation,and Investment Style of International Equity Managers

This paper evaluates the performance of 114 international equity managers over the January 1988–December 1997 period. Performance tests are conducted using Sharpe (1966) and Jensen (1968) performance methodologies. The managers are divided into mutual fund (n=54) and separately managed fund (n=60) investment management categories. Each management category is further divided by foreign and world (global) investment objectives. Three major findings are reported. First, international equity managers, on average, were unable to outperform the MSCI World market proxy during the sample period. However, world managers did perform better than their foreign counterparts. Second, geographic asset allocation and equity style allocation decisions enhanced the performance of international managers during the sample period. Third, separately managed funds outperformed mutual funds during the period studied when mutual fund returns are measured net of management fees. The apparent managed performance advantage abates, however, when mutual fund returns are adjusted to include management fees. Thus, we find no significant difference in the performance of the management categories when returns are measured gross of fees.     

销售与运营规划一体化

如果企业能够打造独立的销售与运营规划团队,使之擅长明智决策和有效运营,那么就很有可能发展成未来的全球领袖