Competitive equilibrium with unawareness in economies with production

This paper investigates an extension of the GEI-unawareness framework by Modica et al. (Econ. Theory 12 (1998) 259) to economies with entrepreneurial production. Existence of equilibrium is guaranteed given decreasing returns to scale. Firm's value and investment decision in equilibrium are characterized. An example of commodity innovation shows that the effect of different degrees of awareness on investment decisions depend upon the degree of risk aversion. In the case of log preferences unawareness may not matter for commodity innovation, although this depends on other preference features.     

Cost-effectiveness of amisulpride compared with risperidone in patients with schizophrenia

SUMMARY

Amisulpride is an atypical antipsychotic, which has demonstrated efficacy across the range of symptoms of schizophrenia. This study compares the treatment costs of amisulpride (including drug costs, hospital costs, and costs of clinician and nurse visits) with those of risperidone over a 6-month treatment period, from the perspective of the UK National Health Service. Resource utilisation data were collected alongside an international, multicentre clinical trial comparing amisulpride (400-1000 mg/day) with risperidone (4-10 mg/day) in 198 patients with schizophrenia. As this trial demonstrated that amisulpride had at least equivalent efficacy to risperidone, the present study was a cost-minimisation analysis. Unit cost data for the UK were obtained from published sources and applied to the clinical data to calculate direct treatment costs. Amisulpride was associated with lower drug acquisition costs and lower resource utilisation costs than risperidone, although the differences did not reach statistical significance. Overall, the average total cost per patient for 6 months of treatment with amisulpride (£12,673; 95% CI: 10,628,14,717) was £2,145 less than for risperidone (£14,818; 95% CI: 12,323,17,312). These findings are similar to those of a previous study that compared the treatment costs of amisulpride with those of haloperidol, and found that

amisulpride was associated with significantly lower direct treatment costs than haloperidol. Amisulpride is a valuable treatment option in patients with schizophrenia.     

Reputation with equal discounting in repeated games with strictly conflicting interests

We analyze reputation effects in two-player repeated games of strictly conflicting interests. In such games, player 1 has a commitment action such that a best reply to it gives player 1 the highest individually rational payoff and player 2 the minmax payoff. Players have equal discount factors. With positive probability player 1 is a type who chooses the commitment action after every history. We show that player 1's payoff converges to the maximally feasible payoff when the discount factor converges to one. This contrasts with failures of reputation effects for equal discount factors that have been demonstrated in the literature.     

Costs associated with adverse events in patients with metastatic renal cell carcinoma

Objective:

To estimate adverse event (AE) costs in patients receiving targeted therapies for the first line treatment of metastatic renal cell carcinoma (mRCC).

Methods:

Retrospective study based on healthcare claims data for patients with mRCC, aged ≥18 years, receiving first-line treatment with targeted therapies. AEs of interest comprised of abdominal pain, back pain, diarrhea, dyspnea, extremity pain, fatigue/asthenia, hand-foot syndrome, hypertension, lymphopenia, nausea/vomiting, neutropenia, proteinuria, and thrombocytopenia. Healthcare encounters for AEs were based on ICD-9-CM diagnosis/procedure codes on healthcare claims. AE costs were examined over a 30-day period, beginning with the date of first mention of AE, and were estimated based on the difference in total costs between patients with and without events. Drug costs of targeted agents were excluded from the analysis. Multivariate generalized linear models with a log-link function and gamma response probability distribution were utilized to control for differences in baseline characteristics between patients with and without evidence of AEs.

Results:

A total of 533 patients were included in this analysis: 418 patients with AE and 115 patients without AE. Baseline characteristics were generally similar between patients in the two groups. The GLM-based estimate of incremental 30-day post-event costs among patients with evidence of any adverse events was $9807 (95% CI?=?$4386–$22,947). For all types of adverse events examined, the estimated difference in costs between evented and non-evented patients was positive; the 95% CI did not include zero for all of the adverse events considered, except hypertension and proteinurea. Study limitations include errors of commission/omission, especially as they may affect case-finding methods that rely on ICD-9-CM diagnosis and procedure codes, as was the case in the current study.

Conclusion:

Costs associated with AEs of first-line targeted therapies are substantial in patients with mRCC. Efforts to prevent and/or better manage these events may reduce overall healthcare costs.     

米非司酮片联合米索前列醇片在带器宫内早孕中的应用

目的探讨米非司酮片联合米索前列醇片在带器宫内早孕中减少并发症的作用。方法选取2010年2月至2014年2月本院接诊的B超提示带器宫内妊娠6~10周要求终止妊娠且无禁忌证的63例患者,随机将其分为观察组(n=32例)与对照组(n=31例),观察组患者予以米非司酮片联合米索前列醇片后行清宫取环术,对照组患者直接行人工流产取环术,观察两组患者的取环情况。结果观察组宫颈松弛程度、取环难度、人流综合征的发生情况均优于对照组,手术时间、胚囊排出时间均短于对照组,差异有统计学意义(P均<0.05)。结论带器宫内早孕口服米非司酮片联合米索前列醇片再行清宫取环术的效果优于直接行人工流产取环术,患者宫颈松弛效果理想,清宫完全,手术时间短,易取环,人流综合征发生率低。     

Learning with bounded memory in games

We study learning with bounded memory in zero-sum repeated games with one-sided incomplete information. The uninformed player has only a fixed number of memory states available. His strategy is to choose a transition rule from state to state, and an action rule, which is a map from each memory state to the set of actions. We show that the equilibrium transition rule involves randomization only in the intermediate memory states. Such randomization, or less frequent updating, is interpreted as a way of testing the opponent, which generates inertia in the player's behavior and is the main short-run bias in information processing exhibited by the bounded memory player.     

Fair allocation in networks with externalities

I prove existence and uniqueness of a component efficient and fair allocation rule when the value of the network is allowed to exhibit any type of externalities across its components. This is done by means of a new specification of the value function, generalizing partial results appearing in Myerson [Myerson, R.B., 1977a. Graphs and cooperation in games. Math. Operations Res. 2, 225–229], Feldman [Feldman, B.E., 1996. Bargaining, coalition formation and value. PhD dissertation. State University of New York at Stony Brook] and Jackson and Wolinsky [Jackson, M.O., Wolinsky, A., 1996. A strategic model of social and economic networks. J. Econ. Theory 71, 44–74]. This component efficient and fair allocation rule is found closely related to an extension of the Shapley value to TU-games in partition function form proposed by Myerson [Myerson, R.B., 1977b. Values of games in partition function form. Int. J. Game Theory 6 (1), 23–31].     

Efficiency in coalition games with externalities

A natural extension of superadditivity is not sufficient to imply that the grand coalition is efficient when externalities are present. We provide a condition, analogous to convexity, that is sufficient for the grand coalition to be efficient and show that this also implies that the (appropriately defined) core is nonempty. Moreover, we propose a mechanism which implements the most efficient partition for all coalition formation games and characterizes the resulting payoff division.     

Renegotiation in Repeated Games with Side-Payments

We consider repeated games with side-payments: players have an endowment of wealth in each period in which transfers can be made. We show that if endowments are large enough and the common discount factor high enough, then a strongly renegotiation–proof equilibrium (SRP) in the sense of Farrell and Maskin exists. As the discount factor goes to 1, the set of SRP payoffs converges to the set of efficient, individually rational payoffs. These results provide a justification for the efficiency principle when agreements are not enforceable. Journal of Economic Literature Classification Numbers: C73, D23, L14.     

Optimum taxation with errors in administration

The paper compares the welfare levels which can be achieved by two distinct tax regimes: lump-sum taxation, where one attempts to identify individuals and allocate transfers or subsidies on the basis of characteristics, and income taxation, where characteristics are not observed but personal incomes are measured and taxed. Where there are no errors in classifying individuals, lump-sum taxation is superior, but, where mistakes are made in the allocation of lump-sum grants or subsidies, income taxation may be more attractive. The level of errors where the regimes are equally desirable in terms of social welfare is computed in simple models following that of Feldstein (1973). Where there is strong aversion to inequality, then income taxation becomes preferable at quite small errors.In analysing income taxation it is shown that in the Feldstein model with endogenous wages the marginal tax rate (in optimum income taxation) on the more skilled is negative and that on the less skilled is positive in contrast to the standard results [see Seade (1977)] with exogenous wages.     

Learning in games with unstable equilibria

We propose a new concept for the analysis of games, the TASP, which gives a precise prediction about non-equilibrium play in games whose Nash equilibria are mixed and are unstable under fictitious play-like learning. We show that, when players learn using weighted stochastic fictitious play and so place greater weight on recent experience, the time average of play often converges in these “unstable” games, even while mixed strategies and beliefs continue to cycle. This time average, the TASP, is related to the cycle identified by Shapley [L.S. Shapley, Some topics in two person games, in: M. Dresher, et al. (Eds.), Advances in Game Theory, Princeton University Press, Princeton, 1964]. The TASP can be close to or quite distinct from Nash equilibrium.     

Information Policy in Tournaments with Sabotage

Sabotage is one of the main problems of tournament‐like reward schemes. Workers who are leading in a tournament are more dangerous rivals, and are therefore sabotaged more heavily. This implies that there is an extra cost to becoming a leader and, hence, to choosing high productive effort in the early stages of a tournament. The incentives to exert productive effort are thereby reduced. We show that this problem can be solved by concealing intermediate information on the performances of workers (i.e., by clever information management). Moreover, we offer experimental evidence indicating that such information management does increase productive efforts.     

Stationary equilibria in bargaining with externalities

This paper studies infinite-horizon bargaining between a seller and multiple buyers when externalities are present. We extend the analysis in Jehiel and Moldovanu by allowing for both pure and mixed equilibria [Jehiel, P., Moldovanu, B., 1995a. Cyclical delay in bargaining with externalities. Rev. Econ. Stud. 62, 619–637]. A characterization of the stationary subgame perfect equilibria in generic games is presented. Equilibria with delay exist only for strong positive externalities. Since each buyer receives a positive payoff when the seller makes an agreement with some other buyer, positive externalities induce a war of attrition between buyers.     

Voting in small networks with cross-pressure

We present a model of participation in elections in small networks, in which citizens suffer from cross-pressures if voting against the alternative preferred by some of their social contacts. We analyze how the existence of cross-pressures may shape voting decisions, and so, political outcomes; and how parties may exploit this effect to their interest. We characterize the strong perfect equilibria of the game and show that, in equilibrium, the social network determines which party wins the election. We also show that to dispose of the citizens better connected in the network with the other faction is not a guarantee to win the election.