Population monotonic path schemes for simple games

A path scheme for a game is composed of a path, i.e., a sequence of coalitions that is formed during the coalition formation process and a scheme, i.e., a payoff vector for each coalition in the path. A path scheme is called population monotonic if a player’s payoff does not decrease as the path coalition grows. In this study, we focus on Shapley path schemes of simple games in which for every path coalition the Shapley value of the associated subgame provides the allocation at hand. Obviously, each Shapley path scheme of a game is population monotonic if and only if the Shapley allocation scheme of the game is population monotonic in the sense of Sprumont (Games Econ Behav 2:378–394, 1990). We prove that a simple game allows for population monotonic Shapley path schemes if and only if the game is balanced. Moreover, the Shapley path scheme of a specific path is population monotonic if and only if the first winning coalition that is formed along the path contains every minimal winning coalition. We also show that each Shapley path scheme of a simple game is population monotonic if and only if the set of veto players of the game is a winning coalition. Extensions of these results to other efficient probabilistic values are discussed.     

Ideology and Reality: Representation and Participation in Local Service Management Evaluating the Case of the Israeli Community Service Centre--Matnas

Correspondence to Dr Uri Yanay Paul Baerwald School of Social Work The Hebrew University of Jerusalem Mt. Scopus, Jerusalem, 91905 Israel Summary Recent trends in social policy and administration encouragecitizen representation. This is based on the ideological assumptionthat representation yields participation and citizen participationultimately secures the interests of the poor and less visiblegroups in the community. In the Israeli network of CommunityService Centres (Matnas) citizen involvement was establishedby selecting or inviting residents to represent the communityalongside other delegates forming a local Board. Research findings indicate that the resulting ‘representativeparticipation’, operated contrary to expectations. Thelay local representatives who were presumed to represent thedisadvantaged of the community reported them as last priority,whereas the professionals representing various organizationson the Mamas Boards claimed to represent them as first priority.Meeting attendance records of the different representatives(a measure of participation) support this finding.     

Ethnicity and Clients' Social Worker Preference: The Israeli Experience

Correspondence to Prof. E. D. Jaffe, Paul Baerwald School of Social Work, Hebrew University of Jerusalem, Mount Scopus, Jerusalem, Israel 91905. Summary Israel's society contains three large ethnic subgroups, oneof Western (Ashkenazi) origin, another from Middle-Eastern (Sephardi)background, and an Arab population group. Social stratificationalong ethnic lines is still common, particularly in the socialservices and human services professions. This article describes an empirical research study of how ethnicstereotypes among Ashkenazi and Sephardi Israeli welfare clientsaffect their preference for Ashkenazi or Sephardi social workhelpers, and compares their responses with other Israeli populationgroups. Using a projective test based on passport photos, itwas found that very clear ethnic preferences exist among bothAshkenazi and Sephardi respondents, and that Sephardi respondents,including Sephardi welfare clients, most often prefer to betreated by Ashkenazi social workers. The cross-cultural, cross-nationalimplications of these findings for ethnic relations, the socialservices and the social work profession are discussed.     

Eligibility Criteria for Cash Assistance for Older and Disabled People in Hungary: A Model for Countries in Passage from a Planned to a Market Economy

Correspondence to Ruth Landau, Paul Baerwald School of Social Work, The Hebrew University of Jerusalem, Mount Scopus, Jerusalem, Israel. Summary The political and economic changes presently taking place inthe Central and Eastern European countries are accompanied byprofound social changes for which, in terms of personal well-being,older and disabled people pay the highest price. Having lostthe security of a minimum standard of living, many are exposedto poverty in its broadest sense. The collapse of governmentalarrangements to provide for the minimum needs of this populationled to the establishment of non-governmental voluntary socialagencies. Unfortunately, these are characterized by limitedresources on the one hand, and lack of trained and skilled socialwork staff on the other. Based on the experience of a Hungariannon-governmental social agency, a model for eligibility criteriafor cash assistance under these circumstances, taking vulnerabilityas a key concept, is suggested for the benefit and dignity ofthose most in need.     

Characterizations of the β- and the Degree Network Power Measure

A symmetric network consists of a set of positions and a set of bilateral links between these positions. For every symmetric network we define a cooperative transferable utility game that measures the “power” of each coalition of positions in the network. Applying the Shapley value to this game yields a network power measure, the β-measure, which reflects the power of the individual positions in the network. Applying this power distribution method iteratively yields a limit distribution, which turns out to be proportional to the well-known degree measure. We compare the β-measure and degree measure by providing characterizations, which differ only in the normalization that is used.      

Uncertainty with Partial Information on the Possibility of the Events

The Choquet expected utility model deals with nonadditive probabilities (or capacities). Their dependence on the information the decision-maker has about the possibility of the events is taken into account. Two kinds of information are examined: interval information (for instance, the percentage of white balls in an urn is between 60% and 100%) and comparative information (for instance, the information that there are more white balls than black ones). Some implications are shown with regard to the core of the capacity and to two additive measures which can be derived from capacities: the Shapley value and the nucleolus. Interval information bounds prove to be satisfied by all probabilities in the core, but they are not necessarily satisfied by the nucleolus (when the core is empty) and the Shapley value. We must introduce the constrained nucleolus in order for these bounds to be satisfied, while the Shapley value does not seem to be adjustable. On the contrary, comparative information inequalities prove to be not necessarily satisfied by all probabilities in the core and we must introduce the constrained core in order for these inequalities be satisfied. However, both the nucleolus and the Shapley value satisfy the comparative information inequalities, and the Shapley value does it more strictly than the nucleolus. This revised version was published online in June 2006 with corrections to the Cover Date.     

The Professional Standing of Work with Elderly Persons among Social Work Trainees

Correspondence to Dr Howard Litwin, Paul Baerwald School of Social Work, The Hebrew University, Mount Scopus, 91905, Jerusalem, Israel. Summary A random sample of 93 students of social work in Israel werequeried regarding their perception of the professional standingof work with older people. The general ranking given by traineesto this field of practice was moderate to low. Relatively positiveevaluation of the status of gerontological practice, however,was found to be explained by: (1) a traditional view of therole of the elder in society; (2) the perception that peersattribute prestige to such work; and (3) having had a fieldpracticum in the area of ageing; and was inversely related tounderstanding of work with elderly persons as mainly indirectintervention. The implications of these findings for the promotionof social work practice with elderly people in an ageing societyare discussed.     

The Interhuman and What is Common to All: Martin Buber and Sociology

Martin Buber was close to sociology and sociologists from his university years on and in 1938 was head of the new Department of Sociology at the Hebrew University of Jerusalem. Although influenced by Ferdinand Toennies, and George Simmel, he went beyond them in his philosophy of the "interhuman" from which standpoint he also criticized Max Scheler. Focal social concepts of Buber's are "the interhuman"_the dialogical relationship between persons that entails "inclusion," or "imagining the real," making present, and confirmation (compared here with the social psychology of George Herbert Mead); the "essential We" or common cosmos that each helps to build by speech-with-meaning from his or her unique stance; the distinction between the "political principle" of government and the "social principle" of fellowship and social spontaneity; and the philosophy of community that led Buber to a federalistic socialism and the vision of restructuring society into a "community of communities".     

Full Employment: An Outmoded Objective in a Technological Age—Rejoinder

This paper challenges the assumption that technological change is beneficial because it results in efficient resource allocation. The introduction of technology in a period of low economic growth will merely distribute income to a decreasing number of people in jobs. As recent history has shown, this situation is worsened if the employed are not prepared to share their gains with the unemployed.     

Monitoring Interventions with Young Israeli Families

Correspondence to Dr Rami Benbenishty, School of Social Work, Hebrew University, Jerusalem, Israel 91905. Summary This paper describes a study monitoring interventions with familiestreated by a welfare agency in Jerusalem, Israel. The treatmentapproach is eclectic and is based mainly on a view of the familyas a system and on task-centred and problem solving orientationsto family treatment. Sixty families were studied. The clients'median age was about 30 years old and the median number of childrenwas two per family. The clients approached the welfare agencyfor four main reasons: financial difficulties (especially heavydebts), severe health problems and disabilities, marital difficulties,and problems in raising children. The practitioners identifiedin two thirds of the families dangerous situations that neededimmediate attention. A repeated measures design utilizing several outcome measureswas used. According to the workers' assessments, based on theCRS (Epstein et al., 1982), functioning improved and progresstoward goal attainment was observed in most families. The magnitudeof changes in functioning, however, was small. The workers'and clients' assessments of change and of goal attainment weremore positive. There were indications of deterioration at followup. The treatment outcomes are discussed in light of the clientand treatment characteristics. Changes in client selection,length of treatment, and an active follow up strategy are suggested.     

A note on deriving rank-dependent utility using additive joint receipts

Luce and Fishburn (1991) derived a general rank-dependent utility model using an operation ⊕ of joint receipt. Their argument rested on an empirically supported property (now) calledsegregation and on the assumption that utility is additive over ⊕. This note generalizes that conclusion to the case where utility need not be additive over ⊕, but rather is of a more general form, which they derived but did not use in their article. Tversky and Kahneman (1992), conjecturing that the joint receipt of two sums of money is simply their sum, criticized that original model because ⊕=+ together with additive utility implies the unacceptable conclusion that the utility of money is proportional to money. In the present generalized theory, if ⊕=+, utility is a negative exponential function of money rather than proportional. Similar results hold for losses. The case of mixed gains and losses is less well understood.     

On utility functions

The von Neumann-Morgenstern (vNM) expected utility criterion is a particular case of a more general utility space structure. The general utility function can take care of the intrinsic utility or disutility of risk.An approximation to this general utility function is the proposed Constant Elasticities of Value and Risk (CEVR) function, which is easily applied in specific cases, for instance in psychometric studies of behaviors in the presence of certain or uncertain gains or losses.     

Evaluating Time Streams of Income: Discounting What?

For decisions whose consequences accrue over time, there are several possible techniques to compute total utility. One is to discount utilities of future consequences at some appropriate rate. The second is to discount per-period certainty equivalents. And the third is to compute net present values (NPVs) of various possible streams and to then apply the utility function to these net present values. We find that the best approach is to first compute NPVs of various possible income streams and then take the utility of such NPVs. We show the drawbacks of other alternative models of evaluating income streams. The article discusses the advantages of the power and logarithmic forms in the modeling of time preference. These are the only forms for which utility of income and utility of consumption are strategically equivalent. Further, these forms permit the flexibility in the choice of a time period (e.g., monthly or quarterly) without modifying the utility function, thus simplifying analysis.     

Reference Wealth Effects in Sequential Choice

It is argued that in order to accommodate experimentally-observed choice patterns, it is not enough to model the utility function as being dependent on changes from a reference wealth point. Instead, individuals should be modeled as treating decisions as part of an identifiable sequence of decisions, and utility should be a function of reference wealth, income so far from the sequence, and payoffs from the current decision. The three-argument utility function allows for risk aversion over gains and risk seeking over losses for the first choice in the sequence, and for the house money and break-even effects in later decisions.     

Recursive expected utility and the separation of attitudes towards risk and ambiguity: an experimental study

We use the multiple price list method and a recursive expected utility theory of smooth ambiguity to separate out attitude towards risk from that towards ambiguity. Based on this separation, we investigate if there are differences in agent behaviour under uncertainty over gain amounts vis-a-vis uncertainty over loss amounts. On an aggregate level, we find that (i) subjects are risk averse over gains and risk seeking over losses, displaying a “reflection effect” and (ii) they are ambiguity neutral over gains and are mildly ambiguity seeking over losses. Further analysis shows that on an individual level, and with respect to both risky and ambiguous prospects, there is limited incidence of a reflection effect where subjects are risk/ambiguity averse (seeking) in gains and seeking (averse) in losses, though this incidence is higher for ambiguous prospects. A very high proportion of such cases of reflection exhibit risk (ambiguity) aversion in gains and risk (ambiguity) seeking in losses, with the reverse effect being significantly present in the case of risk but almost absent in case of ambiguity. Our results suggest that reflection across gains and losses is not a stable individual characteristic, but depends upon whether the form of uncertainty is precise or ambiguous, since we rarely find an individual who exhibits reflection in both risky and ambiguous prospects. We also find that correlations between attitudes towards risk and ambiguity were domain dependent.      

A comparison of non-transferable utility values

Three values for non-transferable utility games -- the Harsanyi NTU-value, the Shapley NTU-value, and the Maschler--Owen consistent NTU-value -- are compared in a simple example.     

Trade sophistication in developing countries: Does export destination matter?

We investigate whether exports to developed economies stimulate export sophistication (represented by UNCTAD’s index of export similarity) in developing countries. Results from fixed-effects estimations suggest that exporting to developed economies enhances the sophistication of exports in the exporting country but there are diminishing returns to this effect. We also find non-linear effects from FDI and income on export sophistication with the effect of income exhibiting diminishing returns which suggests that the gains from exporting to developed economies are higher for lower-income countries; i.e., as income increases, the gains taper off. We discuss the policy implications of these results.     

A Plea For Greater Attention on the Data in Policy Analysis

The technical difficulties associated with building and solving applied general equilibrium (GE) models seem to have distracted our attention from the data. In this article, we forcefully stress that whatever the sophistication of the GE analysis, it is only worth the quality of the supporting data it utilizes. We first highlight an example of a flagrant flaw in officially published input–output data (factor–income shares) by an LDC (Turkey), which many researchers use without question. We then make use of an applied GE model to evaluate the dynamic gains for Turkey from currently debated trade policy options and compare the predictions using conservatively adjusted, rather than official, data on factor shares. We show that the predicted welfare gains are not only of a different order of magnitude, but in some cases, of a different sign; hence, suggesting contradictory policy recommendations.     

Trade and poverty nexus: A case study of Sri Lanka

The link between trade liberalisation and poverty has become one of the most debated topics in recent years. There is a growing body of empirical literature on this topic and many studies provide mixed results. In this study, Sri Lanka is used as a detailed case study and a computable general equilibrium (CGE) approach is used as an analytical framework to examine the trade-poverty nexus. The results suggest that, liberalisation of the manufacturing industries is more pro-poor than that of the agricultural industries. Overall, this study suggests that trade reforms may widen the income gap between the rich and the poor creating uneven gains across different household groups in Sri Lanka. While short-term complementary policies are needed to compensate vulnerable income groups, long-term policies are needed to make gains from trade liberalisation more inclusive and equitable to maintain economic and political stability in Sri Lanka.