BUSCADOR RECOLECTA

In local social migrations, agents move from their initial location looking for a better local social environment. Social migrations processes do not change the number of social agents of a given type (i.e., the empirical distribution of the population) but their spatial location. Although cellular automata seems to appear as a natural approach to model of social migrations, the evolution of the configuration through a cellular automata might induce a new configuration wherein the number of agents of each type might be actually modified. This article provides a characterization of these cellular automata rules such that for any initial empirical distribution, the evolution of the configuration through a cellular automata of such class induces a new configuration with the same empirical distribution as the initial one, as required to model local social migrations. A class of sequences is defined in order to establish a sufficient condition to maintain this invariance property., Support from projects JC2009-00189 and MC238206 is also gratefully acknowledged. J. M. Benito-Ostolaza acknowledges financial support from Project ECO2009-12836 of the Ministry of Science and Innovation of Spain and Project ECO2012-34202 of Ministry of Economy and Competitivity of Spain. Likewise, P. Hernandez and J. Vila thank the Spanish Ministry of Science and Innovation and the European Feder Funds for financial support under project ECO2010-20584 and ECO2013-46550-R as well as the Prometeo Programme Funds PROMETEO/2009/068 and PROMETEOII/2013/019.

The final publication is available at Springer via http://dx.doi.org/10.1007/s00355-012-0716-9, In this paper, we axiomatically study how to measure the similarity of preferences in a group of individuals. For simplicity, we refer to this as the cohesiveness. First, we provide axioms that characterize a family of linear and additive measures whose intersection is a partial ordinal criterion similar to first order stochastic dominance. The introduction of some additional properties isolates a one-parameter subfamily. This parameter evaluates the effect on the cohesiveness if one individual changes his ranking on a single pair of objects, as a function of how many of the remaining individuals in the group rank the first object over the second and vice versa. Finally, we characterize the focal measures of this subfamily separately showing that they coincide with measures constructed using two, at first sight, totally different approaches suggested in the literature., The author Jorge Alcalde-Unzu gratefully acknowledges financial support from the
Spanish Ministry of Education and Science, through the projects ECO2009-11213 and ECO2009-12836.
The author Marc Vorsatz gratefully acknowledges financial support from the Spanish Ministry of Education
and Science (through the project ECO2009-07530) and from the Spanish Ministry of Economy and Competitiveness
(through the project ECO2012-31985).

This paper explores optimality of contracts and incentives when the principal (public organisation) can undertake investments to change agents’ (public workers) identity. In the model, workers within the organisation can have different identities. We develop a principal-agent dynamical model with moral hazard, which captures the possibility of affecting this workers’ identity through contracts offered by the firm. In the model, identity is a motivation source which reduces agents’ disutility from effort. We use the term identity to refer to a situation in which the worker shares the organisational objectives and views herself as a part of the organisation. Contrary, we use the term conflict to refer to a situation in which workers behave self-interested and frequently in the opposite way of the organisation. We assume that identity can be achieved when principal include mission-sense developing investments in contracts. By mission we mean a single culture that is shared by all the members of an organization. We discuss the conditions under which spending resources in changing workers’ identity and invest in this kind of motivational capital is optimal for organisations. Our results may help to inform public firms’ managers about the optimal design of incentive schemes and policies. For instance, we conclude that investing in motivational capital is the best option in the long run whereas pure monetary incentives works better in the short run., Thanks to the Spanish Ministry of Science and Innovation for financial support of this project (Project ECO2009-12836).

This paper explores optimal incentive schemes in public health institutions when agents (doctors) are intrinsically motivated. We develop a principal-agent dynamic model with moral hazard in which agents’ intrinsic motivation could be promoted (crowding-in) by combining monetary and non-monetary rewards, but could also be discouraged (crowding-out) when the health manager uses only monetary incentives. We discuss the conditions under which investing in doctors’ motivational capital by the use of well designed nonmonetary rewards is optimal for the health organizations manager. Our results show that such investments will be more efficient than pure monetary incentives in the long run. We will also prove that when doctors are riskaverse, it is profitable for the health manager to invest in motivational capital., The authors would like to thank the Spanish Ministry of Science and Innovation for financial support (Project ECO2009-12836).

This paper develops a general model of common resource extraction where we introduce payments for environmental services to encourage resource users to give up extraction. The goal is to reach a balance between resource use and conservation. As the essence of conservation is dynamic, we use a dynamic model to study the implementation of the compensation scheme. A stable heterogeneous equilibrium can be reached where both extractors and non-extractors live together. We analyze how the success of the compensation depends on factors such as the elasticity of demand and the biological characteristics of the resource., Financial support from projects ECO2009-12836 and ECO2012-34202 of the Spanish Minister of Science and Innovation.

Where the contracts are incomplete, the resulting co-ordination problems may be attenuated if workers are intrinsically motivated to do the work. It is established by theoretical and empirical literature that workers within public organizations are intrinsically motivated to exert effort doing the job and have a strong sense of social agents with the mission of providing collective goods to citizens and tax payers. This paper is an empirical pilot study in the health care sector using methods of Qualitative Analysis research. We run semistructured interviews á-la-Bewley to sixteen physicians of Navarre’s health Care Servicio Navarro de Salud-Osasunbidea (SNS-O). The objective of the work is twofold: first, to find empirical evidence about doctors’ non-monetary motives and second, to find evidence about how these non-monetary motives shape doctors’ behavior. We formulate several testable hypotheses: (1) Doctors are intrinsically motivated agents, (2) Economic incentives and control policies may crowd-out intrinsic motivation and (3) Well designed incentives may crowd-in agents intrinsic motivation. Results confirm the hypotheses formulated above and coming from our theoretical findings [11], [12]. Finally, we also found empirical evidence of conflict between political advisors or health managers (principals) and physicians (agents). Results are a step forward in the optimal design of incentive schemes and policies which crowd in doctors’ intrinsic motivation., The authors are grateful to the Spanish Ministry of Science and Innovation for financial support of this project (Project ECO2009-12836).

The final publication is available at Springer via http://dx.doi.org/10.1007/s00355-012-0689-8, We present a model that is closely related to the so-called models of choice under complete uncertainty, in which the agent has no information about the probability of the outcomes. There are two approaches within the said models: the state space-based approach, which takes into account the possible states of nature and the correspondence between states and outcomes; and the set-based approach, which ignores such information, and solves certain difficulties arising from the state space-based approach. Kelsey (Int Econ Rev 34:297–308, 1993) incorporates into a state space-based framework the assumption that the agent has ordinal information about the likelihood of the states. This paper incorporates this same assumption into a set-based framework, thus filling a theoretical gap in the literature. Compared to the set-based models of choice under complete uncertainty we introduce the information about the ordinal likelihood of the outcomes while, compared to Kelsey’s approach, we incorporate the advantages of describing uncertainty environments from the set-based perspective. We present an axiomatic study that includes adaptations of some of the axioms found in the related literature and we characterize some rules featuring different combinations of information about the ordinal likelihood of the outcomes and information about their desirability., We acknowledge financial support
from the Spanish Ministry of Science and Technology (Projects ECO2008-04756, ECO2009-11213,
ECO2009-12836 and Ramón y Cajal program), the Junta de Castilla y León (Project VA092A08), FEDER,
and the Barcelona Economics Program of CREA.

This paper explores optimality of contracts and incentives when the principal (public organization) can undertake investments to change agents’ (public workers) identity. In the model, workers within the organization can have different identities. We develop a principal-agent dynamical model with moral hazard, which captures the possibility of affecting this workers’ identity through contracts offered by the firm. In the model, identity is a motivation source which reduces agents’ disutility from effort. We use the term identity to refer to a situation in which the worker shares the organizational objectives and views herself as a part of the organization. Contrary, we use the term conflict to refer to a situation in which workers behave self-interested and frequently in the opposite way of the organisation. We assume that the principal can include investments to foster identity in contracts. Think for instance in developing a single culture that is shared by all the members of an organization. We discuss the conditions under which spending resources in changing workers’ identity and invest in this kind of motivational capital is optimal for organizations. Our results may help to inform public firms’ managers about the optimal design of incentive schemes and policies. For instance, we conclude that investing in motivational capital is the best option in the long run whereas pure monetary incentives works better in the short run., The authors would like to thank the Spanish Ministry of Science and Innovation for financial support of these projects (ECO2009-12836, ECO2012-34202).

The final publication is available at Springer via http://dx.doi.org/10.1007/s10888-011-9165-4, Rankings to evaluate opportunity distributions present in most of the literature judge a policy (change from one distribution of opportunities to another) on the basis of the changes created and, thus, independently of the original situation. This paper proposes a group of axioms capturing the idea that rankings of equality of opportunities might consider not only the changes promoted, but also the initial situation in society. The combination of this group of axioms with other well-established properties enables us to characterize two families of new opportunity distribution rankings. The first family weighs each individual’s percentage share in the total number of opportunities, while the second weighs opportunities depending on how many agents have them available., Financial support
from the Spanish Ministry of Education through grants ECO2008-04756, ECO2009-
11213, ECO2009-12836, Juan de la Cierva and Ramon y Cajal programs, FEDER, and
the Barcelona Economics Program of CREA is gratefully acknowledged.

This paper analyzes to what extent the definition of property rights affects cropping decisions when these decisions generate negative externalities. To that end, we implement an experimental study where agents make cropping decisions in two different treatments: private and common land. The results show that there are no statistically significant differences between the two treatments in the contribution to the negative externality, thus revealing that the definition of property rights does not affect cropping decision in this context. Furthermore, our findings indicate that the implication of the agents in activities generating negative externalities tends to increase over time, thus amplifying its adverse consequences., Financial support from projects ECO2009-12836, ECO2012-34202 and ECO2011-29314-C02-01.

This essay deals with the notion and content of freedom of choice proposing a new set up and a new family of measures for this concept which is, indeed, an ethical value of paramount importance in a well ordered and open society. Following some ideas of John StuartMill, we propose that freedom of choice has to be understood not in a single stage of choice, but in the ordered collection of choices that a person can make in her life.We then suggest to represent a life in a tree structure, where each node
represents a state of life and the edges between nodes will represent possible decisions in life. In this new framework, we propose a set of axioms that imply the following family of measures of lifetime’s freedom of choice: the lifetime’s freedom of choice has to be evaluated by a weighted sum of all possible states of life an individual might visit, with weights representing the number of decisions the individual took to reach that state., Financial support
from the Spanish Ministry of Education through grants ECO2008-04756, ECO2009-11213, ECO2009-
12836, Ramon y Cajal program, FEDER, and the Barcelona Economics Program of CREA is gratefully
acknowledged.

This paper investigates the use of egalitarian criteria to select allocations in bankruptcy problems. In our work, we characterize the sets of Lorenz maximal elements for these problems. We show that the allocation selected by the Proportional Rule is the only allocation that belongs to all these Lorenz maximal sets. We prove that the Talmud Rule selects the lexicographic maximal element within a certain set. We introduce and analyze a new sharing rule for bankruptcy problems that shares strong similarities with the Talmud Rule., J. Arin acknowledges financial support from Project 9/UPV00031.321-15352/2003 of the University of the Basque Country, Projects SEJ-2006-05455 and ECO2009-11213 of the Ministry of Education and Science of Spain and Project GIC07/146-IT-377-07 of the Basque Goverment. Likewise, J. Benito acknowledges financial support from Projects SEJ-2006-11510 and ECO2009-12836 of the Ministry of Education and Science of Spain.

This paper explores the conditions that characterize the optimality for a principal (health manager) to undertake investments to motivate agents (doctors). In the model, doctors are intrinsically motivated and can have different identities. We develop a principal agent dynamical model with moral hazard, which captures the possibility of affecting doctors’ intrinsic motivation and identity through contracts offered by the health manager. Identity and intrinsic motivation of the doctor can be undermined (crowding-out) or enhanced (crowding-in) by incentive policies and monetary rewards. When motivations beyond the money play a role in the agents behaviour, the optimality of the equilibrium outcomes may be altered. Intrinsic motivation is defined as doctor’s experienced enjoyment from doing her work and commit toward a mission. By “full” identity we mean a situation in which the doctor shares the organizational objectives and views herself as a part of the organization. We assume that “full” identity can be achieved when health managers include mission supportive investments in contracts. This also crowds in intrinsic motivation. However, crowding out occurs when the health manager uses only pure monetary rewards to incentivize doctors with the goal of drive their actions in his own interest. Solving the model, we are allowed to make comparative statics and discuss the conditions under which spending resources to invest in motivational capital, is optimal for the health organization’s manager. Our results may help to inform policy-makers about optimal policy design and optimal management of health organizations. For instance, we conclude that investing in motivational capital is more likely to be profitable in the long run whereas mere monetary incentives are more likely to be optimal in the short run., The authors acknowledge financial support from the Spanish Ministry of Science and Innovation (Project ECO2009-12836).