"We argue that the postwar baby boom [in the United States] caused substantial fluctuations in both the economic rewards to education and educational attainment over the last 3 decades. If substitutability between young and old workers diminishes with education, the present value of lifetime earnings for a boom cohort is depressed more for highly educated workers, reducing incentives for educational attainment. The opposite is true for pre- and postboom cohorts. The diminishing substitutability hypothesis explains the declines in both the returns to college and college completion rates in the 1970s and predicts a substantial increase in educational attainment for postboomers." 相似文献
Background: Validation of overall survival (OS) extrapolations of immune-checkpoint inhibitors (ICIs) during the National Institute for Health and Care Excellence (NICE) Single Technology Assessment (STA) process is limited due to data still maturing at the time of submission. Inaccurate extrapolation may lead to inappropriate decision-making. The availability of more mature trial data facilitates a retrospective analysis of the plausibility and validity of initial extrapolations. This study compares these extrapolations to subsequently available longer-term data.
Methods: A systematic search of completed NICE appraisals of ICIs from March 2000 to December 2017 was performed. A targeted search was also undertaken to procure published OS data from the pivotal clinical trials for each identified STA made available post-submission to NICE. Initial Kaplan-Meier curves and associated extrapolations from NICE documentation were extracted to compare the accuracy of OS projections versus the most mature data.
Results: The review identified 11 STAs, of which 10 provided OS data upon submission to NICE. The extrapolations undertaken considered parametric or piecewise survival models. Additional data cut-offs provided a mean of 18 months of OS beyond the end of the original data. Initial extrapolations typically under-estimated OS from the most mature data cut-off by 0.4–2.7%, depending on the choice of assessment method and use of the manufacturer- or ERG-preferred extrapolation.
Conclusion: Long-term extrapolation of OS is required for NICE STAs based on initial immature OS data. The results of this study demonstrate that the initial OS extrapolations employed by manufacturers and ERGs generally predicted OS reasonably well when compared to more mature data (when available), although on average they appeared to underestimate OS. This review and validation shows that, while the choice of OS extrapolation is uncertain, the methods adopted are generally aligned with later-published follow-up data and appear appropriate for informing HTA decisions. 相似文献
We consider a country with two factors and two industries, each of which faces technical and price uncertainty. Entrepreneurs choose outputs in order to maximize the expected utility of profits. They also draw factor payments and purchase consumption goods after the uncertainty isresolved. They enter and exit from an industry according to whether participation there increases their expected utility. Within this model, the validity of the propositions of neoclassical trade theory depends on how the entrepreneurs' entry decisions are affected by parameter changes via their roles as risk bearers, consumers and factor owners. 相似文献
The phrase mixed economy of welfare refers to the observation that the provision of public services in western countries frequently involves the participation of other sectors in addition to government. For example, a service may be privately financed and produced but regulated by government, financed by government subsidies or vouchers but produced privately, or produced by a commercial or voluntary organization under contract to government. But such different ways in which government can arrange public service supply by no means exhaust the varieties of arrangements in a mixed economic system. Other examples include alternative institutional arrangements for articulating consumer wants for public services, evaluating consumer satisfaction, and holding the producers of services accountable for their performance.This paper examines the role of official public advisory bodies and private, voluntary associations whose purposes are to improve services to users of U.S. public transportation. At variance with some of the theory of political economy, it is found that the public and private consumer organizations generally enjoy a symbiotic rather than substitute or competitive relationship with one another, and that both kinds of organizations arise and complement each other in addressing the problems of consumers of a government service produced under monopoly conditions.
Die Beteiligung mehrerer Wirtschaftssektoren bei der Versorgung mit öffentlichen Diensten — der Fall der amerikanischen Verbraucher-Agenturen für öffentlichen Nahverkehr
Zusammenfassung Der Ausdruck mixed economy of welfare bezieht sich auf die Beobachtung, daß die Versorgung mit öffentlichen Gütern in westlichen Ländern häufig nicht allein durch den Staat erfolgt. So kann zum Beispiel ein öffentliches Gut privat finanziert und hergestellt werden, aber unter öffentlicher Aufsicht stehen, oder es kann von der öffentlichen Hand bezahlt aber privat produziert werden, oder es kann durch eine kommerzielle oder gemeinnützige Organisation in Absprache mit staatlichen Stellen produziert werden. Ebenso gibt es Fälle, wo öffentlicher und privater Hersteller eines vergleichbaren Gutes verschiedene Marktseggmente versorgen. Beispielsweise stehen in den USA den Bürgern, die mit öffentlichen Schulen unzufrieden sind, private Schulen zur Verfügung.Diese Beispiele zeigen, auf welchen unterschiedlichen Wegen die Versorgung mit öffentlichen Gütern rangiert werden kann. Solche angebotsorientierten Beispiele zeigen aber nur einen Teil der möglichen Sektorverbindungen in einer Mischwirtschaft. Andere Beispiele treffen eher die Nachfrageseite bei öffentlichen Gütern, insbesondere die institutionellen Möglichkeiten für die Artikulation von Verbraucherwünschen hinsichtlich öffentlicher Güter für die Erfassung der Zufriedenheit und dafür, daß die Anbieter öffentlicher Güter für ihr Leistungsniveau einstehen müssen. Solche Beispiele zeigen, daß Einrichtungen wie Kommissionen für öffentliche Dienste, Departements für Konsumentenfragen, Ombudsmänner und eine Vielzahl privater und freiwilliger Organisationen in unterschiedlichster Weise tätig werden, um die Interessen von Bürgern zu schützen, die öffentliche Leistungen in Anspruch nehmen.Der vorliegende Beitrag betrachtet solche Einrichtungen für öffentlichen Nah- und Fernverkehr in den USA. Ebenso wie in England gibt es hier sowohl offizielle öffentliche Beratungsgremien wie auch private freiwillige Einrichtungen, deren Zielsetzung ganz ähnlich sind, nämlich die Leistungen der öffentlichen Verkehrsunternehmungen zu verbessern. Der Beitrag berichtet über die Ergebnisse einer empirischen Studie beider Arten von Gremien und versucht die Rolle beider Arten in einer Mischwirtschaft zu beschreiben. Insbesondere versucht der Beitrag, zu erklären, warum beide Arten von Gremien entstehen, welches Verhältnis sie zu einander und zu den Transportunternehmen haben. Im Gegensatz zu manchen theoretischen Annahmen erwies sich, daß öffentliche und private Verbraucherorganisationen weniger in einem substitutiven oder wettbewerblichen Verhältnis zueinander stehen, sondern eher eine Symbiose miteinander bilden, und daß sich beide Arten von Organisationen häufig bei der Behandlung von Problemen ergänzen.The author is indebted to his former student and research assistant Chester Phillips for carrying out the survey for this paper. He would also like to thank his colleague Richard Silkman for insightful comments and suggestions on the first draft and Beverly Dolinsky of the Permanent Citizens Advisory Committee to the MTA in New York City for the time and information she provided. Finally, the author wants to thank Ken Judge for providing the stimulus to write this paper through the invitation to participate in the 1983 Social Administration Association Conference in Canterbury, England, where this paper was first presented, and Harry Weiner for arranging support to allow attendance at that conference.
Dennis R. Young is a Professor at W. Averell Harriman College for Policy Analysis and Public Management, State University of New York at Stony Brook, Stony Brook, New York 11794, USA. 相似文献
This article investigates the role of the annual report and the annual general meeting (AGM) in the context of NHS trusts. The authors report the results of a questionnaire survey of every NHS trust in the UK. Significant variation in the approach taken within a common framework of accountability was found. In general, there seems to be little public demand for trusts' annual reports and attendance at their AGMs was low. The research indicates possibilities of extending annual reporting in the public sector beyond the annual report and AGM and discloses innovative ways that trusts have attempted to overcome the limited interest of stakeholders produced by the traditional reporting mechanisms. 相似文献
Correlation estimates for returns between individual properties are subject to large inherent uncertainties due to limits on the amount of data that is likely to be available for the foreseeable future. After allowance for correlation sampling error, it is impossible to distinguish on an ex ante basis between the risk-reduction capabilities of mean-variance portfolio selection models and naive diversification without regard to property type or geographical location. The naive portfolio diversification strategies of typical institutional real estate portfolio managers are rational responses to limitations on the informational content of statistical analyses of historical real estate data. 相似文献
This study investigates the effectiveness of the Tokyo Stock Exchange (TSE)-traded Japanese 10-year JGB futures contract to hedge portfolios of Japanese bonds of differing maturity and credit quality. The bond portfolios examined are Government, AAA-, and AA-rated Eurobonds with maturities of 2, 3, 5, 7, 10, and 20 years. Consistent with the recent literature, the study employs univariate methods for calculating hedge ratios based on levels, first differences, and percentage change of each series. Out-of-sample forecasting is used to determine the effectiveness of the calculated hedge ratios for each of the bond portfolios and to determine which approach to calculating hedge ratios is the most effective. The results show that this particular futures contract does provide a good hedge, particularly for those bond terms closest to the 10-year term of the contract. There is some evidence, although not strong, that JGBs are better hedged than AAA and AA bonds. Investors should take some caution when using this futures contract to hedge bond portfolios of different maturities and credit ratings. 相似文献
This paper investigates the problem faced by firms that transport containers by truck in an environment with resource constraints. The considered area is export-dominant. As a result, there are three types of container movements as inbound full, outbound full, and inbound empty movements. Both the time windows at the terminal and at the customers’ places and the operation times are considered. Empty containers are also regarded as separate transportation resources besides trucks. The total operating time including waiting time of all the trucks in operation is minimized. The problem is first formulated as a directed graph and then mathematically modeled based on the graph. It falls into a multiple traveling salesman problem with time windows (m-TSPTW) with resource constraints. An algorithm based on reactive tabu search (RTS) is developed to solve the problem. A number of randomly generated examples indicate that the algorithm can be applied to the real world. 相似文献
Cover and Pecorino (2005) claim that the March 1933 departure from the gold standard is the most probable break point ushering in an era of longer U.S. expansions, both absolutely and relative to subsequent recessions. Their analysis is based on cycle durations as defined by National Bureau of Economic Research (NBER) reference dates. However, much of macroeconomic analysis is based on (i) growth cycles (i.e., periods when the economy's production is above or below trend) rather than absolute increases or decreases in economic activity; and (ii) aggregate time series' volatility as the prime indicator of macroeconomic stability. In light of this, we reevaluate the March 1933 break point. First, using HP‐filtered quarterly gross national product (GNP), our analysis of growth cycle durations still implies a break point near 1933. Second, we test for structural breaks in the volatility of GNP growth rates and deviations from trends. These tests suggest a structural break considerably later than 1933, perhaps as late as the 1950s. 相似文献