War and peace: Third-party intervention in conflict

This paper develops a simple sequential-move game to characterize the endogeneity of third-party intervention in conflict. We show how a third party's “intervention technology” interacts with the canonical “conflict technologies” of two rival parties in affecting the sub-game perfect Nash equilibrium outcome. From the perspective of deterrence strategy, we find that it is more costly for a third party to support an ally to deter a challenger from attacking (i.e., to maintain peace or acquiescence), as compared to the alternative case when the third party supports the ally to gain a disputed territory by attacking (i.e., to create war), ceteris paribus. However, an optimally intervening third party can be either “peace-making”, “peace-breaking”, or neither depending on the characteristics of the conflict and the stakes the third party holds with each of the rival parties.     

An experimental analysis of cooperation and productivity in the trust game

In the standard trust game the surplus is increased by the risk taking first mover while cooperation by the second mover is a one-to-one transfer. This paper reports results from experiments in which the reverse holds; the first mover’s risky trust is not productive and the second mover’s cooperation is productive. This subtle difference significantly lowers the likelihood of trust but increases the likelihood of cooperation conditional on trust. Evidence is presented that the change in trust is consistent with first movers failing to anticipate the later result. Drawing upon the analogy that the trust game represents a model of exchange, the results suggest that markets should be organized so that the buyer moves first and not the seller as in the original trust game.

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Electronic Supplementary Material  The online version of this article () contains supplementary material, which is available to authorized users.      

Second-party and third-party punishment in a public goods experiment

We experimentally investigate whether third-party punishment is more effective than second-party punishment to increase public goods contribution. In our experiment, third parties first played the standard public goods game and then made punishment decisions as independent bystanders. We find that third parties punished more frequently, severely and less antisocially, resulting in a higher contribution level than that driven by second-party punishment. The third party’s exaggerated emotion towards free riders is proposed to explain their superior punishment effectiveness.     

The pre-marital investment game

Two sides of a finite marriage market engage in costly investment and are then matched assortatively. The purpose of the investment is solely to improve the quality of the match that the trader can attain in the second stage. The paper studies the limits of equilibrium of these finite matching games as the number of traders gets large. It is shown that mixed Nash equilibria in the finite games converge to degenerate pure strategy equilibria in the limit in which both sides of the market invest too much.     

Dissertation abstract: Reputational benefits of altruism and altruistic punishment

Recent studies in experimental economics have shown that many people have other-regarding preferences, potentially including preferences for altruism, reciprocity, and fairness. It is useful to investigate why people possess such preferences and what functional purpose they might serve outside the laboratory, because evolutionary and social learning perspectives both predict that cooperative sentiments should only exist if they bring benefits that outweigh the costs of other-regarding behavior. Theories of costly signaling suggest that altruistic acts may function (with or without intention) as signals of unobservable qualities such as resources or cooperative intent, and altruists may benefit (possibly unintentionally) from the advertisement of such qualities. After reviewing the theories that could potentially account for the evolution of altruism (Chapter 1), I test some predictions about cooperation derived from costly signaling theory. In Chapter 2, I show that participants in experimental public goods games were more cooperative when they had cues that they could benefit from having a good reputation, and that there was apparently some competition to be the most generous group member. Furthermore, in subsequent trust games, people tended to trust high public goods contributors more than low contributors. Chapter 3 failed to find evidence that granting high status to people makes them more likely to contribute to public goods or punish free-riders, but there was suggestive evidence that physical proximity to the experimenter affected contributions and punishment. In Chapter 4, I found that people tended to trust others who were willing to incur costs to punish those who free-ride on group cooperation provided that such punishment was justified, and men were more punitive than women. In Chapter 5, I show that women find altruistic men more desirable than neutral men for long-term relationships. Together, these results suggest that humans do treat altruism as a signal of willingness to be cooperative. These findings are discussed with respect to the adaptive design of cooperative sentiments as well as the current debate over group selection. Dissertation: Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontarion Currently: Post-Doc, Department of Neurobiology & Behavior, Cornell University     

When punishment fails: Research on sanctions, intentions and non-cooperation

People can become less cooperative when threatened with sanctions, and previous research suggests both “intentions” and incentives underlie this effect. We report data from an experiment aimed at determining the relative importance of intentions and incentives in producing non-cooperative behavior. Participants play a one-shot investment experiment in pairs. Investors send an amount to trustees, request a return on this investment and, in some treatments, can threaten sanctions to enforce their requests. Decisions by trustees facing threats imposed (or not) by investors are compared to decisions by trustees facing threats imposed (or not) by nature. When not threatened, trustees typically decide to return a positive amount less than the investor requested. When threatened this decision becomes least common. If the request is large relative to the sanction then most trustees return nothing. If the request is small, trustees typically return the requested amount. These results do not vary with investors' intentions.     

Inequity aversion and trustees' reciprocity in the trust game

The introduction of inequity concerns into the Trust Game gives rise to complementary concepts of conditional trustworthiness and unconditional untrustworthiness. When the inequity concern is not accounted for, unconditional untrustworthiness is overestimated. The high proportion of trustees adopting the equal division behavioural norm suggests that an unequal distribution of show-up fees may deter trustors from placing trust, and may eventually reduce the incentive to cooperate for both players. It also follows that increases in income inequality can explain declines in self-reported trust in high-income countries.     

Inferring repeated-game strategies from actions: evidence from trust game experiments

Summary. Combining a strategy model, an inference procedure and a new experimental design, we map sequences of observed actions in repeated games to unobserved strategies that reflect decision-makers’ plans. We demonstrate the method by studying two institutional settings with distinct theoretical predictions. We find that almost all strategies inferred are best responses to one of the inferred strategies of other players, and in one of the settings almost all of the inferred strategies, which include triggers to punish non-cooperators, are consistent with equilibrium strategies. By developing a method to infer unobserved repeated-game strategies from actions, we take a step toward making game theory a more applied tool, bridging a gap between theory and observed behavior.Received: 23 December 2002, Revised: 19 April 2005, JEL Classification Numbers: C72, C80, C90.The authors are indebted for discussions with Ray Battalio, David Cooper, Robin Dubin, John Duffy, Ellen Garbarino, Susan Helper, Margaret Meyer, John Miller, Jim Rebitzer, Mari Rege, Al Roth, and John Van Huyck. The authors also benefited from discussants at economic department seminars at Case Western Reserve, McMaster and McGill University, University of Pittsburgh, SUNY-Stony Brook, and Texas A&M, and participants at the 2002 European Winter Meeting of the Econometric Society. We are grateful for the financial support provided by the Department of Economics at the University of Pittsburgh and Case Western Reserve University.     

护理干预对肠镜下结肠息肉切除效果的影响

目的探讨护理干预在肠镜下结肠息肉切除术中的临床应用效果。方法选取2013年3月～2013年6月在我院进行肠镜下结肠息肉切除手术治疗的患者350例,随机分为干预组和对照组各175例。两组患者在行肠镜下结肠息肉切除手术的同时,均给予一般常规护理干预模式,而干预组患者则在此基础上采用系统化的综合护理干预模式,并分别对两组患者的临床治疗情况进行深入细致的比较和分析。结果与对照组相比,干预组患者插镜成功的比率显著提高,而术后出现腹胀和肛门便意感的比率则显著降低,差别均具有统计学意义（P＜0.05）;与此同时,干预组患者术中发生肠穿孔和肠出血的比率均有所减少,但均未呈现出显著性差异（P＞0.05）。结论系统性综合护理干预模式对于肠镜下结肠息肉切除手术患者临床治疗效果的改善及并发症的减少均具有极其重要的意义,适于临床推广和应用。     

Whatever you say, your reputation precedes you: Observation and cheap talk in the trust game

Behavior in trust games has been linked to general notions of trust and trustworthiness, important components of social capital. In the equilibrium of a trust game, the investor does not invest, foreseeing that the allocator would keep all of the returns. We use a human-subjects experiment to test the effects of changes to the game designed to increase cooperation and efficiency. We add a pre-play stage in which the investor receives a cheap-talk message from the allocator, observes the allocator's previous decision, or both. None of these changes alter the game's theoretical predictions. We find that allowing observation results in substantially higher cooperation and efficiency, but cheap talk has little effect.     

综合干预在高血压病患者中的应用探讨

目的探讨综合干预对高血压病的治疗作用及对其后的影响。方法对高血压病患者进行定点、定点监测,同时进行家庭随访,综合干预,并与对照组进行前瞻性对照研究。结果入组前患者收缩压(157.5±9.0)mmHg(1mmHg=0.133kPa)、舒张压(95.0±16.5)mmHg,3年后收缩压(130.6±11.0)mmHg、舒张压(80.0±12.0)mmHg,与对照组比较,P<0.001;两组之间的降压幅度比较,P<0.05。患者的生活习惯有了改善,生活质量明显提高,并发症、致残率和病死率是对照组的20%。两组90项症状比较,干预组总分下降具有显著意义。结论高血压病严重威胁健康,社区家庭干预和健康宣教疗效肯定;公众教育、专业人员教育和高血压病患者教育还任重而道远。     

Foreign direct investment and bilateral investment treaties: An international political perspective

This paper investigates the effect of the implementation of bilateral investment treaties (BITs) on the bilateral stocks of foreign direct investment (FDI). We argue that the understanding of how BITs affect FDI requires recognizing that multinational enterprises (MNEs) are not Stateless and that their investment return may well depend on the quality of political relations between the home and host countries. Using bilateral FDI data and event data to measure political interactions between countries, we show that the effect of the entry into force of a BIT crucially depends on the quality of political relations between the signatory countries; it increases FDI more between countries with tense relationships than between friendly countries. We also find evidence that BITs and good domestic institutions are complementary. BITs should therefore be understood as a mechanism for host governments to credibly commit not to expropriate investors in the future.     

Friction model and foreign exchange market intervention

The friction model is consistent with the hypothesis that a central bank intervenes in a foreign exchange market only if the necessity grows beyond certain thresholds. For this feature, the model is adopted in some recent studies as an attractive central bank reaction function. However, with official data on Federal Reserve and Bundesbank intervention, this paper shows that the friction model's advantage relative to a linear model may be negligible in terms of RMSE and MAE of in-sample fitting and out-of-sample forecasts. The implication is that intervention decisions are at the monetary authorities' discretion rather than dictated by a rule.     

An investment contest to influence environmental policy

In an investment contest for environmental policy, polluters and victims of pollution invest in an increase of their marginal benefits of pollution and environmental quality, respectively. These investments influence time-consistent environmental policy. Investments will exceed their optimal level. The more victims there are, the lower aggregate investment, the lower payoffs for the victims and the higher payoffs for the polluters. The more polluters there are, the higher aggregate investment and the lower payoffs for polluters and victims. Asymmetries between polluter and victim result in less overinvestment and bias environmental policy in favour of the less productive side.     

Trust and trustworthiness in games: An experimental study of intergenerational advice

This paper investigates the development of conventions of trust in what we call intergenerational games, i.e., games played by a sequence of non-overplapping agents, who pass on advice on how to play the game across adjacent generations of players. Using the trust game of Berg et al. (1995) as our experimental decision problem, advice seems to decrease the amount of trustthat evolves when this game in played in an inter-generational manner in that it decreases the amount of money sent from Senders to Returners. Ironically, advice increases trustworthinessin that Returners tend to send more back. Further, subjects appear to follows conventions of reciprocity in that they tend to Send more if they think the Returners acted in a “kind” manner, where kind means the Sender sent more money than the receiver expected. Finally, while we find a causal relationship running from trustworthiness to trust, the opposite can not be established. We note that many of our results can only be achieved using the tools offered by inter-generational games. The inter-generational advice offered provides information not available when games are played in their static form. Combining that information with elicited beliefs of the Senders and Returners adds even more information that can be used to investigate the motives that subjects have for doing what they do. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users. JEL Classification C91 · C72 Resources for this research were provided by National Science Foundation grants SBR-9709962 and SBR-9709079 and by both the Center for Experimental Social Science and the C.V. Starr Center for Applied Economics at New York University. We would like to thank Shachar Kariv for both his comments and research assistance. We also thank Mikhael Shor and Judy Goldberg for research assistance, and Yevgeniy Tovshteyn for computer programming.     

Nonlinear exchange rate dynamics under stochastic official intervention

Many studies employ non-linear models to explain or forecast the exchange rate and find their superiority. This article builds an exchange rate model of managed float under conditional official intervention. In the model, the government minimizes social loss through a trade-off between targeting the exchange rate and lowering intervention costs. We obtain an endogenous threshold model and derive an analytical solution of the exchange rate stochastic interventions. The implication of a managed float causing a lower volatility of the exchange rate has been found by past empirical studies. Our model provides not only a justification for the central banks' conditional interventions but also a rationale for the use of regime-switching models of two states (intervention vs. non-intervention) in the empirical studies of exchange rates.     

An introduction to the symposium on behavioral game theory

This article introduces the articles contained in the symposium on behavioral game theory. I break economic experiments studying game theory into three broad classes: (1) experiments studying and possibly modifying the assumptions that serve as foundations for game theory; (2) experiments that perform economic engineering, testing existing institutions with the aim of designing better ones; and (3) experiments designed to test theories which apply game theory to fields such as industrial organization.      

'Tying the manager's hands': constraining opportunistic managerial intervention

We discuss and examine empirically a firm-level equivalent ofthe ancient problem of ‘tying the King's hands’,namely how to avoid managerial intervention that is undertakento reap private benefits but is harmful to overall value creation,that is, ‘managerial opportunism’. The link frommanagerial intervention to firm-level value-creation is moderatedby employee motivation. Thus, intervention in the form of managersoverruling employees or reneging on delegation may demotivateemployees, particularly when the intervention is perceived asbeing unfair, undertaken for personal gain, etc. We argue thata number of mechanisms, such as managers staking their personalreputation, employees controlling important assets, strong tradeunions, etc. may function as constraints on managerial proclivitiesto intervene, thus reducing the problem of managerial opportunism.We derive four hypotheses from these ideas, and test them, usingpath-analysis, on a rich dataset, based on 329 firms in theSpanish food and electric/electronic industries.     

Information acquisition in the ultimatum game: An experimental study

We experimentally investigate if free information disadvantages a player relative to when information is unavailable. We study an Ultimatum game where the Proposer, before making an offer, can obtain free information about the Responder's minimum acceptable offer. Theoretically, the Proposer should obtain the information and play a best reply to the Responder's minimum acceptable offer. Thus the Responder should get the largest share of the surplus. We find that an increasing number of Proposers become informed over time. Moreover, the proportion of Proposers who use the information to maximize money earnings increases over time. The majority of information-acquiring Proposers, however, refuse to offer more than one-half and play a best reply only to Responders who accept offers of one-half or less. This, together with a substantial proportion of Proposers who choose to remain uninformed, means that the availability of free information backfires for Proposers only by a little. Electronic Supplementary Material Supplementary material is available in the online version of this article at . JEL Classification C70, D63, D80     

Incremental third-party costs associated with COPD exacerbations: a retrospective claims analysis

Abstract

Background:

Exacerbations are a major contributor to the large burden of treating chronic obstructive pulmonary disease (COPD). Estimates of exacerbation costs in the United States are limited.

Objective:

To estimate incremental costs associated with COPD exacerbation, particularly severe exacerbation, in the United States.

Methods:

COPD patients with at least one exacerbation were identified in the Thomson Reuters MarketScan administrative claims database. A COPD exacerbation was defined as patient use of oral or parenteral corticosteroids on the same day or within 7 days following a claim with a COPD diagnosis. Severe exacerbation was further defined if the exacerbation was associated with hospitalization or death. Healthcare costs and exacerbations were evaluated at quarterly intervals starting from patients’ first observed claim with COPD diagnostic code in the database. Incremental costs associated with exacerbation were estimated as cost differences between quarters with exacerbation and quarters without exacerbation.

Results:

A total of 2644,174 patient-quarters, derived from 228,978 COPD patients, were included in the analysis. The average patient was followed an average of 2.9 years. The mean total cost was $17,016 per patient-quarter with severe exacerbation, $6628 per patient-quarter with non-severe exacerbation, an average of $8726 per patient-quarters with any exacerbation compared to $4762 per patient-quarter with no exacerbation. After adjusting for patient demographics, the mean incremental total cost was $11,261 per patient-quarter with severe exacerbation, $1509 per patient-quarter for non-severe exacerbation, and $3439 per patient-quarter with any exacerbation compared with patient-quarters with no exacerbation.

Limitations:

The method used for defining exacerbations does not capture mild exacerbations. Additional limitations exist due to the nature of claims data.

Conclusions:

Exacerbations, especially severe ones, result in a significant economic burden for third-party payers. Effective management of COPD and prevention of exacerbations may lead to improved patient outcomes and reduction in total healthcare costs for long-term management of COPD.