Wild bids. Gambling for resurrection in procurement contracts

This paper analyzes the problem of abnormally low tenders in theprocurement process. Limited liability causes firms in a bad financialsituation to bid more aggressively than good firms in the procurementauction. Therefore, it is more likely that the winning firm is a firm infinancial difficulties with a high risk of bankruptcy. The paper analyzesthe different regulatory practices to face this problem with a specialemphasis on surety bonds used e.g. in the US. We characterize the optimalsurety bond and show that it does not coincide with the current USregulation. In particular we show that under a natural assumption the USregulation is too expensive and provides overinsurance to the problem ofabnormally low tenders.

A process approach to the utility for gambling

This paper argues that any specific utility or disutility for gamblingmust be excluded from expected utility because such a theory is consequentialwhile a pleasure or displeasure for gambling is a matter of process, notof consequences. A (dis)utility for gambling is modeled as a process utilitywhich monotonically combines with expected utility restricted to consequences.This allows for a process (dis)utility for gambling to be revealed. Asan illustration, the model shows how empirical observations in the Allaisparadox can reveal a process disutility of gambling. A more general modelof rational behavior combining processes and consequences is then proposedand discussed.

Gambling in Spain: update on experience, research and policy

AIMS: To describe the current situation of gambling in Spain, sketching its history and discussing the regulations and legislation currently in force within the framework of the European Union (EU), and to review the epidemiology of gambling in Spain, the self-help groups and professional treatments available, and their potential effectiveness. METHODS: A systematic computerized search was performed in three databases (EMBASE, PubMed and PsychINFO, including articles and chapters) and the reference lists from previous reviews to obtain some of the most relevant studies published up to now on the topic of pathologic gambling in Spain. RESULTS: Similar to other EU countries, Spain has a high prevalence of pathologic gambling, focused on specific culturally bounded types of gambling. Expenditure in online gaming has risen significantly in the last few years, prompting the Spanish government to draft new legislation to regulate gaming. CONCLUSIONS: The gaming industry is expected to be one of the fastest growing sectors in Spain in the coming years owing to the rise of new technologies and the development of online gaming

D��ficits y sesgos neurocognitivos y afectivos en la toma de decisiones de jugadores patol��gios y otros trastornos

Los d��ficits y sesgos tanto cognitivos como afectivos han sido fuente creciente de inter��s en el ��mbito de la Neuroci��ncia de los Trastornos Mentales. En este proyecto, que se inicia en 2004 y finaliza a finales de 2008, se han estudiado los siguientes Trastornos Mentales: Juego Patol��gico (JP), Trastornos de la Conducta Alimentaria (TCA) y Trastornos Depresivos. En esta memoria nos centraremos en resumir parte de los resultados obtenidos en un estudio sobre JP y toma de decisiones (articulo en revisi��n y pendiente de aceptaci��n) y otro de funcionamiento ejecutivo en JP y Bulimia Nerviosa (BN) (art��culo en prensa). Resumiento el primer estudio los JP (N=32) muestran un proceso de toma de decisiones sesgado por la b��squeda de recompensa en forma de elevada toma de riesgos en comparaci��n con Controles Sanos (CS). Tambi��n se observan d��ficits en flexibilidad cognitiva pero no en control inhibitorio entre JP y CS. Los resultados descartan miop��a conductual para lo toma de decisiones en JP, pero apuntan a un sesgo cognitivo-afectivo, en el que el control de los impulsos jugar��a un papel relevante, en forma de ilusi��n de control, para los procesos de toma de decisiones con recompensa inmediata pero con castigo diferido, medidos por una prueba de toma de decisiones (IGT ABCD). En el segundo estudio, bas��ndose en las vulnerabilidadades compartidas descritas entre JP y BN se compar�� el funcionamiento ejecutivo de mujeres con JP y BN. Tras la administraci��n del WCST y Stroop y ajustando el an��lisis por edad y educaci��n, las JP mostraron mayor afectaci��n, en concreto mayor porcentaje de errores perservaritvos, menor nivel de respuestas conceptuales y mayor n��mero de ensayos administrados, mientras que el grupo de BN mostr�� mayor porcentaje de errores no persevarativos. Ambas, mujeres JP y BN mostraron disfunci��n ejecutiva en relaci��n a los CS pero con diferentes correlatos espec��fcos.

Percepci��n de las consecuencias del consumo de tabaco en fumadores adictos al juego

En una muestra de 34 adictos al juego en tratamiento, se examinan las caracter��sticas deconsumo de tabaco de los sujetos fumadores y la influencia de las consecuencias percibidas dela conducta de fumar en funci��n de las etapas de cambio (Prochaska, DiClemente y Norcross,1992). Los resultados muestran que, aunque los porcentajes de fumadores doblan a los existentesen la poblaci��n general, las personas fumadoras adictas al juego est��n representadas en lasdiferentes etapas de cambio con porcentajes parecidos a los de dicha poblaci��n. Por otra parte,no se ha encontrado relaci��n entre el nivel de dependencia medido con el Test de Fagerstr��m yla etapa de cambio. En cuanto a la influencia de las consecuencias percibidas del consumo detabaco, en general los sujetos tienden a conceder mayor importancia a los perjuicios que a losbeneficios de fumar. En los an��lisis en funci��n de las etapas de cambio, se encuentran diferenciassignificativas entre el grupo de los que piensan dejar de fumar en los pr��ximos seis meses,(contempladores y preparados) y el grupo de los que no fuman (exfumadores y no fumadores) enel beneficio ���fumar ayuda a relajarse��� que es m��s valorado por los primeros. Tambi��n seencuentran dichas diferencias entre los precontempladores y los que no fuman en dos perjuicios:���fumar produce a veces dolor de cabeza��� y ���fumar a veces provoca taquicardia��� que son m��svalorados por los segundos. Estos resultados sugieren la conveniencia de realizar las intervencionesm��s adecuadas para cada etapa de cambio, a fin de que las personas adictas al juegopuedan tambi��n tener ��xito en el abandono de la adicci��n al tabaco

Tratamiento farmacol��gico del juego patol��gico

El tratamiento farmacol��gico del juego patol��gico conlleva una serie de dificultades que se pueden relacionar con la ausencia de un sustrato neurobiol��gico universalmente aceptado, altas tasas de abandonos y no cumplimentaci��n del tratamiento, y ausencia de ensayos controlados que comparen diferentes modalidades de tratamiento en la misma poblaci��n. El abordaje farmacol��gico del juego patol��gico se puede reaiizar desde diferentes perspectivas: desde un punto de vista etiopaton��nico, desde el tiatumiento de-las patolog��as asociadas al juego patol��gico e incluso tratatando esta conducta como un s��ntoma de otra patolog��a, como la mania. En las siguientes p��ginas 10s autores intentan revisar 10s diferentes f��rmacos propuestos en varios estudios. Los autores no recomiendan un tratamiento especifico para el juego patol��gico ya que existen diferentes posibilidades seg��n las caracter��sticas del paciente.

On the tractability of the piecewise-linear approximation for general discrete-choice network revenue management

The choice network revenue management (RM) model incorporates customer purchase behavioras customers purchasing products with certain probabilities that are a function of the offeredassortment of products, and is the appropriate model for airline and hotel network revenuemanagement, dynamic sales of bundles, and dynamic assortment optimization. The underlyingstochastic dynamic program is intractable and even its certainty-equivalence approximation, inthe form of a linear program called Choice Deterministic Linear Program (CDLP) is difficultto solve in most cases. The separation problem for CDLP is NP-complete for MNL with justtwo segments when their consideration sets overlap; the affine approximation of the dynamicprogram is NP-complete for even a single-segment MNL. This is in contrast to the independentclass(perfect-segmentation) case where even the piecewise-linear approximation has been shownto be tractable. In this paper we investigate the piecewise-linear approximation for network RMunder a general discrete-choice model of demand. We show that the gap between the CDLP andthe piecewise-linear bounds is within a factor of at most 2. We then show that the piecewiselinearapproximation is polynomially-time solvable for a fixed consideration set size, bringing itinto the realm of tractability for small consideration sets; small consideration sets are a reasonablemodeling tradeoff in many practical applications. Our solution relies on showing that forany discrete-choice model the separation problem for the linear program of the piecewise-linearapproximation can be solved exactly by a Lagrangian relaxation. We give modeling extensionsand show by numerical experiments the improvements from using piecewise-linear approximationfunctions.

Functional connectivity of reward processing in the brain

Controversial results have been reported concerning the neural mechanisms involved in the processing of rewards and punishments. On the one hand, there is evidence suggesting that monetary gains and losses activate a similar fronto-subcortical network. On the other hand, results of recent studies imply that reward and punishment may engage distinct neural mechanisms. Using functional magnetic resonance imaging (fMRI) we investigated both regional and interregional functional connectivity patterns while participants performed a gambling task featuring unexpectedly high monetary gains and losses. Classical univariate statistical analysis showed that monetary gains and losses activated a similar fronto-striatallimbic network, in which main activation peaks were observed bilaterally in the ventral striatum. Functional connectivity analysis showed similar responses for gain and loss conditions in the insular cortex, the amygdala, and the hippocampus that correlated with the activity observed in the seed region ventral striatum, with the connectivity to the amygdala appearing more pronounced after losses. Larger functional connectivity was found to the medial orbitofrontal cortex for negative outcomes. The fact that different functional patterns were obtained with both analyses suggests that the brain activations observed in the classical univariate approach identi��� es the involvement of different functional networks in the current task. These results stress the importance of studying functional connectivity in addition to standard fMRI analysis in reward-related studies.

Microstructural Brain Differences Predict Functional Hemodynamic Responses in a Reward Processing Task

Many aspects of human behavior are driven by rewards, yet different people are differentially sensitive to rewards and punishment. In this study, we showthat white matter microstructure inthe uncinate/inferiorfronto-occipitalfasciculus, defined byfractional anisotropy values derived from diffusion tensor magnetic resonance images, correlates with both short-term (indexed by the fMRI blood oxygenation level-dependent response to reward in the nucleus accumbens) and long-term (indexed by the trait measure sensitivity to punishment) reactivityto rewards.Moreover,traitmeasures of reward processingwere also correlatedwith reward-relatedfunctional activation in the nucleus accumbens. The white matter tract revealed by the correlational analysis connects the anterior temporal lobe with the medial and lateral orbitofrontal cortex and also supplies the ventral striatum. The pattern of strong correlations suggests an intimate relationship betweenwhitematter structure and reward-related behaviorthatmay also play a rolein a number of pathological conditions, such as addiction and pathological gambling.

When decisions of others matter to me: an electrophysiological analysis.

Background: Actions of others may have immediate consequences for oneself. We probed the neural responses associated with the observation of another person"s action using event-related potentials in a modified gambling task. In this task a"performer" bet either a higher or lower number and could win or lose this amount. Three different groups of"observers" were also studied. The first (neutral) group simply observed the performer"s action, which had no consequences for the observers. In the second (parallel) group, wins/losses of the performer were paralleled by similar wins and losses by the observer. In the third (reverse) group, wins of the performer led to a loss of the observer and vice versa. Results: ERPs of the performers showed a mediofrontal feedback related negativity (FRN) to losses. The neutral and parallel observer groups did similarly show an FRN response to the performer"s losses with a topography indistinguishable from that seen in the performers. In the reverse group, however, the FRN occurred for wins of the performer which translated to losses for the observer. Conclusions: Taking into account previous experiments, we suggest that the FRN response in observers is driven by two evaluative processes (a) related to the benefit/loss for oneself and (b) related to the benefit/loss of another person

Functional connectivity of reward processing in the brain

Controversial results have been reported concerning the neural mechanisms involved in the processing of rewards and punishments. On the one hand, there is evidence suggesting that monetary gains and losses activate a similar fronto-subcortical network. On the other hand, results of recent studies imply that reward and punishment may engage distinct neural mechanisms. Using functional magnetic resonance imaging (fMRI) we investigated both regional and interregional functional connectivity patterns while participants performed a gambling task featuring unexpectedly high monetary gains and losses. Classical univariate statistical analysis showed that monetary gains and losses activated a similar fronto-striatallimbic network, in which main activation peaks were observed bilaterally in the ventral striatum. Functional connectivity analysis showed similar responses for gain and loss conditions in the insular cortex, the amygdala, and the hippocampus that correlated with the activity observed in the seed region ventral striatum, with the connectivity to the amygdala appearing more pronounced after losses. Larger functional connectivity was found to the medial orbitofrontal cortex for negative outcomes. The fact that different functional patterns were obtained with both analyses suggests that the brain activations observed in the classical univariate approach identi��� es the involvement of different functional networks in the current task. These results stress the importance of studying functional connectivity in addition to standard fMRI analysis in reward-related studies.