Bootstrap validity for the score test when instruments may be weak

It is well-known that size adjustments based on bootstrapping the t$t$-statistic perform poorly when instruments are weakly correlated with the endogenous explanatory variable. In this paper, we provide a theoretical proof that guarantees the validity of the bootstrap for the score statistic. This theory does not follow from standard results, since the score statistic is not a smooth function of sample means and some parameters are not consistently estimable when the instruments are uncorrelated with the explanatory variable.     

Supply chain challenges. building relationships

Supply chain management is all about software and systems, right? Put in the best technology, sit back, and watch as your processes run smoothly and the savings roll in? Apparently not. When HBR convened a panel of leading thinkers in the field of supply chain management, technology was not top of mind. People and relationships were the dominant issues of the day. The opportunities and problems created by globalization, for example, are requiring companies to establish relationships with new types of suppliers. The ever-present pressure for speed and cost containment is making it even more important to break down stubbornly high internal barriers and establish more effective cross-functional relationships. The costs of failure have never been higher. The leading supply chain performers are applying new technology, new innovations, and process thinking to far greater advantage than the laggards, reaping tremendous gains in all the variables that affect shareholder value: cost, customer service, asset productivity, and revenue generation. And the gap between the leaders and the losers is growing in almost every industry. This roundtable gathered many of the leading thinkers and doers in the field of supply chain management, including practitioners Scott Beth of Intuit, Sandra Morris of Intel, and Chris Gopal of Unisys. David Burt of the University of San Diego and Stanford's Hau Lee bring the latest research from academia. Accenture's William Copacino and the Warren Company's Robert Porter Lynch offer the consultant's perspectives. Together, they take a wide-ranging view of such topics as developing talent, the role of the chief executive, and the latest technologies, exploring both the tactical and the strategic in the current state of supply chain management.     

Operations analysis: Experience and concept

Abstract

The usual introductory, expository articles on operations analysis catch one's eye and hold one's interest through the discussion of examples where particularly novel and clever techniques were used, or where the successes were impressively spectacular. In no sense is this comment derogatory. Those aspects of the subject which have the most dramatic appeal are naturally the best enticement for a newcomer to focus his attention on the subject. For some, this initial contact will be a stimulation to go into the subject more deeply, either as practitioners or as users. For them a more systematic account, including both entertaining and dull aspects, may be worthwhile. The field of operations analysis has now attained sufficient stability that it is possible to draw some conclusions about the ways to obtain the greatest benefits from it, the nature of its investigative procedures, the training of its personnel, and its relationships to previously established fields of study.     

The Education of a Technology Policy Analyst—to Process Management

Technology policy analysis emphasizes logical resolution of issues based on conceptual models, data, and analyses, but this often is not enough to accomplish anything. Policy-makers routinely disregard policy analyses, even when well done, timely, and pertinent to the issues at hand. Process management complements policy analysis by directing attention to the interactions through which disparate interests reconcile their differences to initiate viable action. We pose five questions that constitute a situational analysis decision tree. Based on answers to those questions, we distinguish five action approaches (including ‘do nothing’) that can enhance the utilization of technology analyses. These approaches demand skills, not always paramount in policy analysts, to run processes that engage stakeholders. We illustrate how process management can enhance the utilization of technology policy analysis through a hypothetical case.     

Capital disadvantage: America's failing capital investment system

The U.S. system of allocating investment capital is failing, putting American companies at a serious disadvantage and threatening the long-term growth of the nation's economy. The problem, says Michael Porter, goes beyond the usual formulation of the issue: accusations of "short-termism" by U.S. managers, ineffective corporate governance by directors, or a high cost of capital. The problem involves the external capital allocation system by which capital is provided to companies, as well as the system by which companies allocate capital internally. America's system is marked by fluid capital and a financial focus. Other countries--notably Japan and Germany--have systems with dedicated capital and a focus on corporate position. In global competition, where investment increasingly determines a company's capacity to upgrade and innovate, the U.S. system does not measure up. These conclusions come out of a two-year research project sponsored by the Harvard Business School and the Council on Competitiveness. Porter recommends five far-reaching reforms to make the U.S. system superior to Japan's and Germany's: 1. Improve the present macroeconomic environment. 2. Expand true ownership throughout the system so that directors, managers, employees, and even customers and suppliers hold positions as owners. 3. Align the goals of capital providers, corporations, directors, managers, employees, customers, suppliers, and society. 4. Improve the information used in decision making. 5. Foster more productive modes of interaction and influence among capital providers, corporations, and business units.