We study markets with costly buyer search in which sellers simultaneously post prices. Buyers costlessly observe one or (with probability 1−q) two of the posted prices, and can accept one or pay to search again. The experiment varies q, the search cost, and the number of buyers. Equilibrium theory predicts a unified very low (high) price for q=0 (q=1) and predicts specific distributions of dispersed prices for q=1/3 and 2/3. Actual prices conform closely to the predictions in some treatments. Buyers’ reservation prices are biased away from the extremes, however, and sellers’ prices have positive autocorrelation and cross-sectional correlation. 相似文献
This paper presents a dynamic model that determines the optimal number of deer hunting permit sales, subject to the objective of maximizing the discounted economic benefits stream from both the consumptive and nonconsumptive uses of deer. This bioeconomic model integrates economic benefits estimated using the dichotomous choice contingent valuation method with biological growth constraints on deer. Using a hunting zone in California as a case study, the model found that the optimal levels of buck hunting permits sold should change on a rotational basis over time and that the current practice of not selling doe hunting permits for that zone is non optimal. 相似文献
Tax competition arguments suggest that governments that operate in an open economy (such as local governments) should not and will not rely on non-benefit taxes, such as the income tax. Yet we observe reliance on income taxes by local governments in many countries, and such reliance changes over time. Evidence from a panel data set of 13 OECD countries over the period 1975-1984 suggests that competition between levels of government (resulting in a vertical fiscal externality) and between governments at the same level (resulting in a horizontal fiscal externality) provide some economic rationale for these changes. Moreover, the evidence indicates that the vertical and horizontal fiscal externalities interact. These results have some interesting implications for fiscal policy in the European Union, particularly as the EU continues to evolve. One implication for the EU is that enlargement that increases tax base disparities within the EU (and is not accompanied by an EU-level income tax) will tend to lower national income tax rates, although this must be qualified because it also depends on the mobility of the population. A second implication is that fiscal expansion of the EU to include an EU-level income tax may tend to lower the reliance of national governments on income taxes through the vertical externality, but may also tend to equalize tax bases across countries, and so increase reliance on national income taxes through the horizontal externality. 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
Pareto-Koopmans efficiency in Data Envelopment Analysis (DEA) is extended to stochastic inputs and outputs via probabilistic input-output vector comparisons in a given empirical production (possibility) set. In contrast to other approaches which have used Chance Constrained Programming formulations in DEA, the emphasis here is on joint chance constraints. An assumption of arbitrary but known probability distributions leads to the P-Model of chance constrained programming. A necessary condition for a DMU to be stochastically efficient and a sufficient condition for a DMU to be non-stochastically efficient are provided. Deterministic equivalents using the zero order decision rules of chance constrained programming and multivariate normal distributions take the form of an extended version of the additive model of DEA. Contacts are also maintained with all of the other presently available deterministic DEA models in the form of easily identified extensions which can be used to formalize the treatment of efficiency when stochastic elements are present. 相似文献
Summary The use of general equilibrium models in applied research imposes a discipline in which model structures can easily be compared and contrasted and model results can be interpreted using a well understood and rigorously developed theoretical framework. These features allow researchers to compare results across modeling efforts and to build on the experience of others in deriving results and formulating questions. This paper first presents a brief critical history of applied general equilibrium analysis. It then summarizes the contributions of eight other papers in this issue.We are grateful to Gary Hansen, Ellen McGrattan, and Richard Rogerson for helpful discussions of this paper. We also want to thank the members of the Applied Theory Workshop at the University of Minnesota, who helped referee and edit the papers in this issue: Fernando Alvarez, Raphael Bergoeing, Betsy Caucutt, Ricardo Cavalcanti, Antonia Diaz, Ron Edwards, Andres Erosa, Terry Fitzgerald, Ron Gecan, Doug Gollin, Karine Moe, François Ortalo-Magne, and Marcelo Veracierto. The views expressed herein are those of the authors and not necessarily those of the Federal Reserve Bank of Minneapolis or the Federal Reserve System. 相似文献
Motivated by problems of coordination failure in organizations, we examine how overcoming coordination failure and maintaining
coordination depend on the ability of individuals to observe others’ choices. Subjects’ payoffs depend on coordinating at
high effort levels in a weak-link game. Treatments vary along two dimensions. First, subjects either start with low financial
incentives for coordination, which typically leads to coordination failure, and then are switched to higher incentives or
start with high incentives, which usually yield effective coordination, and are switched to low incentives. Second, as the
key treatment variable, subjects either observe the effort levels chosen by all individuals in their experimental group (full
feedback) or observe only the minimum effort (limited feedback). We find three primary results: (1) When starting from coordination
failure the use of full feedback improves subjects’ ability to overcome coordination failure, (2) When starting with good
coordination the use of full feedback has no effect on subjects’ ability to avoid slipping into coordination failure, and
(3) History-dependence, defined as dependence of current effort levels on past incentives, is strengthened by the use of full
feedback.
Electronic Supplementary Material Supplementary material is available in the online version of this article at
.
JEL Classification C92, D23, J31, L23, M52 相似文献
We construct a laboratory market in which there is a friction in the matching between buyers and sellers. Sellers simultaneously post prices and then buyers simultaneously choose a seller. If more than one buyer chooses the same seller, the seller's single unit is randomly sold to one of them. Our results show a broad consistency with theoretical predictions, although price dispersion exists and is slow to decay. Prices also exceed the equilibrium level when there are only two sellers, and buyers' purchase probabilities are insufficiently responsive to price differences when there are two sellers. 相似文献