Cost sharing with multiple technologies

We study cost sharing problems where gains from cooperation can come from the presence of other agents, such as when agents share their technologies. A simple model is built, where economies of scale are eliminated in order to study this effect. We use as the key axiom the property that, if an agent does not improve the technology of any coalition he joins, he should not get any part of the gain from cooperation. With properties of linearity and symmetry, this axiom characterizes a well-defined set of rules. From this set, we propose a rule derived from the familiar Shapley value. We show that it is the only rule in that set satisfying an upper-limit property on individual cost allocations or a monotonicity property when technology improves. We also derive a distinct rule using a property that ensures that no coalition has an incentive to manipulate the individual demands of its members.     

Strong equilibrium in cost sharing connection games

We study network games in which each player wishes to connect his source and sink, and the cost of each edge is shared among its users either equally (in Fair Connection Games—FCG's) or arbitrarily (in General Connection Games—GCG's). We study the existence and quality of strong equilibria (SE)—strategy profiles from which no coalition can improve the cost of each of its members—in these settings. We show that SE always exist in the following games: (1) Single source and sink FCG's and GCG's. (2) Single source multiple sinks FCG's and GCG's on series parallel graphs. (3) Multi source and sink FCG's on extension parallel graphs. As for the quality of the SE, in any FCG with n players, the cost of any SE is bounded by H(n) (i.e., the harmonic sum), contrasted with the Θ(n) price of anarchy. For any GCG, any SE is optimal.     

Group strategyproof cost sharing: The role of indifferences

Every agent reports his willingness to pay for one unit of a good. A mechanism allocates goods and cost shares to some agents. We characterize the group strategyproof (GSP) mechanisms under two alternative continuity conditions interpreted as tie-breaking rules. With the maximalist rule (MAX) an indifferent agent is always served. With the minimalist rule (MIN) an indifferent agent does not get a unit of the good.GSP and MAX characterize the cross-monotonic mechanisms. These mechanisms are appropriate whenever symmetry is required. On the other hand, GSP and MIN characterize the sequential mechanisms. These mechanisms are appropriate whenever there is scarcity of the good.Our results are independent of an underlying cost function; they unify and strengthen earlier results for particular classes of cost functions.     

The price of anarchy of serial, average and incremental cost sharing

We compute the price of anarchy (PoA) of three familiar demand games, i.e., the smallest ratio of the equilibrium to efficient surplus, over all convex preferences quasi-linear in money. For any convex cost, the PoA is at least in the average and serial games, where n is the number of users. It is zero in the incremental game for piecewise linear cost functions. With quadratic costs, the PoA of the serial game is , and for the average and incremental games. This generalizes if the marginal cost is convex or concave, and its elasticity is bounded.      

On demand responsiveness in additive cost sharing

Under partial responsibility, the ranking of cost shares should never contradict that of demands.The Solidarity axiom says that if agent i demands more, j should not pay more if k pays less. It characterizes the quasi-proportional methods, sharing cost in proportion to `rescaled' demands.Full responsibility rules out cross-subsidization for additively separable costs. Restricting solidarity to submodular cost characterizes the fixed-flow methods, containing the Shapley-Shubik and serial methods.The quasi-proportional methods meet—but most fixed-flow methods fail—Group Monotonicity: if a group of agents increase their demands, not all of them pay less. Serial cost sharing is an exception.     

Sharing the cost of redundant items

We ask how to share the cost of finitely many public goods (items) among users with different needs: some smaller subsets of items are enough to serve the needs of each user, yet the cost of all items must be covered, even if this entails inefficiently paying for redundant items. Typical examples are network connectivity problems when an existing (possibly inefficient) network must be maintained.We axiomatize a family cost ratios based on simple liability indices, one for each agent and for each item, measuring the relative worth of this item across agents, and generating cost allocation rules additive in costs.     

The stand-alone test and decreasing serial cost sharing

Summary. The rule of decreasing serial cost sharing defined in de Frutos [1] over the class of concave cost functions may violate the important stand-alone test. Sufficient conditions for the test to be satisfied are given, in terms of individual rationality as well as coalitional stability. These conditions restrict the shape of the cost function and the distribution of demands. Received: July 29, 1999; revised version: October 4, 1999     

Strong monotonicity in surplus sharing

Summary. We consider three new axioms for surplus sharing problems. The first is strong monotonicity which says that workers should be rewarded for increases in productivity and the second says that productive workers should receive some compensation. The third requires that the surplus sharing rule should be well defined (and continuous on) the set of threshold functions. We show that none of the standard "equitable" mechanisms satisfy any of these axioms and then present a constructive characterization of mechanisms which do. Using this we construct several new mechanisms. These are the Almost Flat mechanism, the Spread Aumann-Shapley mechanism, and the Spread Serial mechanism, which have many desirable properties.Received: 15 September 2002, Revised: 11 March 2003, JEL Classification Numbers: C71, H4.I would like to thank Hervé Moulin, Rich Mclean, Yves Sprumont and an anonymous referee for helpful comments.     

Estimating the economic benefits of acidic rock drainage clean up using cost shares

This paper reports the results of a stated preference study that estimates the economic value for cleaning up acid rock drainage in Colorado's Snake River watershed. In contrast to much of the existing literature, the present study emphasizes benefit estimation for three implementing projects rather than benefit estimation for general changes in water quality or large scale water quality policy. The focus on implementing projects delivers information that is specifically relevant to current decisions being faced in the watershed. While valuation questions in most stated preference studies present costs that have no relation to actual project costs, this study presents a new cost share approach. Project costs are estimated and then valuation questions present different local cost shares to subjects. This approach facilitates stated cost variation necessary for estimating the mean of the distribution of project values without resorting to experimentally designed, fictitious stated costs. In addition to estimating the mean value, which facilitates benefit cost analysis, the study also provides median value estimates, which provide insights into the political feasibility of these projects. Study results suggest that local cost shares on the order of 20%-40%, depending on the project, are politically feasible.     

Minimum cost spanning tree problems with indifferent agents

We consider an extension of minimum cost spanning tree (mcst) problems in which some agents do not need to be connected to the source, but might reduce the cost of others to do so. Even if the cost usually cannot be computed in polynomial time, we extend the characterization of the Kar solution (Kar, 2002) for classic mcst problems. It is obtained by adapting the Equal treatment property: if the cost of the edge between two agents changes, their cost shares are affected in the same manner if they have the same demand. If not, their changes are proportional to each other. We obtain a family of weighted Shapley values. Three interesting solutions in that family are characterized using stability, fairness and manipulation-proofness properties.     

Decreasing absolute prudence: Characterization and applications to second-best risk sharing

In this paper, we provide two basic properties of utility functions u which exhibit decreasing absolute prudence i.e. (− u/u″)′ ≤ 0. These properties are used to examine the allocation of risks in an economy when some agents bear non-transferable risks. We show that it is fair Pareto-efficient to let those with a non-transferable risk bear relatively less of the transferable risk in the economy if and only if absolute prudence is decreasing. In another model, there is a complete set of contingent markets, but some agents have no direct access to them. We examine the fair efficient allocation of risk in a pool gathering a trader and a non-trader. Decreasing absolute prudence provides an upper bound to the share of the pool's risk that should be borne by the trader.     

Serial cost sharing of excludable public goods: general cost functions

Summary. A group of individuals meet to share the cost and determine output allocations of a partial-excludable public good. We demonstrate that, for general cost functions and preferences that satisfy the Spence-Mirlees sorting condition, the serial cost-sharing formula (Moulin, 1994) has remarkable incentive properties. First, a direct economic mechanism that uses the serial formula is coalition strategy-proof, envy-free and satisfies the stand-alone property. Second, the serial mechanism involves partial exclusion, which is important for the reduction of the free-rider problem. Received: June 10, 1996; revised version; February 11, 1997     

Knowledge sharing and the dynamics of social capital

Mutual aid often entails the sharing of knowledge. We investigate how, in turn, knowledge sharing affects the long-run dynamics of mutual aid. In our economy, agents with specific knowledge are “held up” by their principals. Inside communities, agents aid each other by sharing their specific knowledge. This process generates a new type of knowledge which exacerbates the specificity of the existing types and induces more agents to engage in mutual aid. However, since the knowledge generated is shared, it progressively renders agents inside communities more flexible and, thus, less dependent on mutual aid. We characterize conditions under which in the long-run mutual aid spreads or is abandoned.     

企业剩余分享及其产权机理

企业剩余由资本所有者独享向其他要素所有者共同分享的演进是现代企业治理结构发展的一个重要趋势。本文对剩余和剩余分享进行了界定,分析了剩余分享的几种情形,阐释了剩余分享的内在产权机理及其主要途径。     

Risk sharing role of foreign aid in developing countries

The effects of foreign aid on economic growth have been extensively investigated over the past 40 years. However, even though foreign aid can be a significant source of insurance against domestic output shocks for developing countries, its risk-sharing role has not been well explored. Using a sample of 22 developing countries over the period 2003–2013, we estimate the degree of income smoothing generated by foreign aid serving as an effective channel of international income smoothing. In particular, for the period 2003–2008, we estimate that foreign aid offset about 4% of the domestic output shocks. Furthermore, we investigate the determinants of the extent of risk sharing via foreign aid, recognizing the diversification of the originating countries as a key factor. Surprisingly, humanitarian aid seems to have a negative effect, which might be explained by its predominant role in the short run.     

A note on the energy-efficiency investments of an expected cost minimizer

This paper analyzes a consumer's choice between a high-efficiency and a low-efficiency version of an energy-using durable when the expected lifetimes of the two versions differ. A (small) difference in expected lifetimes may induce entirely different implications for the behavior of a cost minimizing consumer, as compared to the case with equal expected lifetimes. The result supplements the explanations for the extremely high discount rates that have been reported for energy efficiency investments. We also provide sufficient conditions for the existence of a reservation property, both in the case of deterministic and of random lifetimes.     

Adjusting for comorbidities in cost of illness studies

Abstract

Motivation:

Differences in cost of illness (COI) methodological approaches have led to disparate results. This analysis examines two sources of this variation: specification of comorbidities in the estimated cost models and assumed prevalence rates used for generating aggregate costs. The study provides guidance in determining which comorbidities are important to include and how to handle uncertainty in optimal model specification and prevalence rate assumptions.

Methods:

Comorbidities are categorized into four types. Type I comorbidities are those that increase the risk of the disease of interest; Type II comorbidities have no causal link to the disease of interest but are, nonetheless, highly correlated with that disease; Type III comorbidities are illnesses that the disease of interest may cause, and Type IV are comorbidities that have no causal link to the disease of interest and are only weakly correlated with that disease. Two-part models are used to estimate the direct costs of rheumatoid arthritis and diabetes mellitus using 2000–2007 Medical Expenditure Panel Survey data.

Results:

COI estimates are sensitive to the specification of comorbidities. The odds of incurring any expenses varies by 71% for diabetes mellitus and by 27% for rheumatoid arthritis, while conditional expenditures (e.g., expenditures among subjects incurring at least some expenditures) vary by 62% and 45%, respectively. Uncertainty in prevalence rates cause costs to vary. A sensitivity analysis estimated the COI for diabetes ranges from $131.7–$172.0 billion, while rheumatoid arthritis varies from $12.8–$26.2 billion.

Conclusions:

The decision to include Type II and Type III comorbidities is crucial in COI studies. Alternative models should be included with and without the Type III comorbidities to gauge the range of cost effects of the disease. In generating costs, alternative values for prevalence rates should be used and a sensitivity analysis should be performed.     

对我国企业成本管理模式选择的探讨

当今的经济环境已经发生很大变化，世界范围内的竞争压力，服务产业的增长，以及信息和生产技术的进步已经改变了经济的性质，并引起众多企业经营经济业务的方式发生显著的改变。经济环境的变化同样催生和加速了新的成本管理模式的诞生，面对复杂的竞争环境，企业如何在传统的成本管理方式和新的成本管理模式之间进行取舍和过渡，已经成为大多数国内企业面临的重要课题、本文围绕我国企业如何建立和运作新的成本管理模式，在全面分析全面成本管理、作业成本管理和成本企画三种成本管理模式的特点和当前我国企业成本管理现状及存在的问题的基础上，提出了我国企业成本管理模式应该以作业成本核算与全面成本管理融合的成本管理新模式，从新的角度给出了问题的解决思路。     

Multi-dimensional risk and the cost of business cycles

This paper analyzes the welfare costs of business cycles when workers face uninsurable idiosyncratic labor income risk. In accordance with the previous literature, this paper decomposes labor income risk into an aggregate and an idiosyncratic component, but in contrast to the previous literature, this paper allows for multiple sources of idiosyncratic labor income risk. Using the multi-dimensional approach to idiosyncratic risk, this paper provides a general characterization of the welfare cost of business cycles when preferences and the (marginal) process of individual labor income in the economy with business cycles are given. The general analysis shows that the introduction of multiple sources of idiosyncratic risk never decreases the cost of business cycles, and strictly increases it if there are cyclical fluctuations across the different sources of risk. This paper also provides a quantitative analysis based on a version of the model that is calibrated to match US labor market data. The quantitative analysis suggests that realistic variations across two particular dimensions of idiosyncratic labor income risk increase the welfare cost of business cycles by a substantial amount.