How individuals choose health insurance: An experimental analysis

An individual choosing a health insurance policy faces a complex decision environment where a large set of alternatives differ on a variety of dimensions. There is uncertainty and the choice is repeated at least once a year. We study decisions and decision strategies in a laboratory experiment where we create a controlled environment that closely mirrors this setting. We use an electronic information board that allows to carefully monitor the individual's decision strategy. The number of alternatives, switching costs, and the speed at which health deteriorates are varied across treatments. We find that most subjects' search is based more on attributes than on policies. Moreover, we find that an increase in the number of alternatives increases decision-making time; makes subjects consider a lower fraction of the available information; makes it more likely that subjects will switch; and decreases the quality of their decisions. The introduction of positive costs of switching makes people switch less often but improves the quality of their decisions. Finally, if health deteriorates only gradually, individuals tend to stick to their current policy too long.     

Peer effects on risk behaviour: the importance of group identity

This paper investigates whether and to what extent group identity plays a role in peer effects on risk behaviour. We run a laboratory experiment in which different levels of group identity are induced through different matching protocols (random or based on individual painting preferences) and the possibility to interact with group members via an online chat in a group task. Risk behaviour is measured by using the Bomb Risk Elicitation Task and peer influence is introduced by giving subjects feedback regarding group members’ previous decisions. We find that subjects are affected by their peers when taking decisions and that group identity influences the magnitude of peer effects: painting preferences matching significantly reduces the heterogeneity in risk behaviour compared with random matching. On the other hand, introducing a group task has no significant effect on behaviour, possibly because interaction does not always contribute to enhancing group identity. Finally, relative riskiness within the group matters and individuals whose peers are riskier than they are take on average riskier decisions, even when controlling for regression to the mean.     

Premium auctions and risk preferences

In a premium auction, the seller offers some “payback”, called premium, to a set of high bidders at the end of the auction. This paper investigates how the performance of such premium tactics is related to the bidders? risk preferences. We analyze a two-stage English premium auction model with symmetric interdependent values, in which the bidders may be risk averse or risk preferring. Upon establishing the existence and uniqueness of a symmetric equilibrium, we show that the premium causes the expected revenue to increase in the bidders? risk tolerance. A “net-premium effect” is key to this result.     

Aggregation of multiple prior opinions

Experts are asked to provide their advice in a situation of uncertainty. They adopt the decision maker?s utility function, but each has a potentially different set of prior probabilities, and so does the decision maker. The decision maker and the experts maximize the minimal expected utility with respect to their sets of priors. We show that a natural Pareto condition is equivalent to the existence of a set Λ of probability vectors over the experts, interpreted as possible allocations of weights to the experts, such that (i) the decision maker?s set of priors is precisely all the weighted-averages of priors, where an expert?s prior is taken from her set and the weight vector is taken from Λ; (ii) the decision maker?s valuation of an act is the minimal weighted valuation, over all weight vectors in Λ, of the experts? valuations.     

Risk attitudes and the stag-hunt game

A stag-hunt game (with the risky and safe actions) has two pure Nash equilibria that are Pareto-rankable. The risky action leads either to the Pareto-superior equilibrium (high payoff) or to out of equilibrium (low payoff) depending on the opponent’s action. Both players may want to obtain high payoff but uncertainty about the opponent’s action may prevent them to take such strategic risk. This paper investigates how information about the risk attitude of an opponent affects a player’s action choice in the stag-hunt game. I find that although a subject’s propensity to choose the risky action depends on her opponent’s risk attitude, it does not depend on her own risk attitude.     

Large deviations and multinomial probit choice

We consider a discrete choice model in which the payoffs to each of an agent?s n actions are subjected to the average of m i.i.d. shocks, and use tools from large deviations theory to characterize the rate of decay of the probability of choosing a given suboptimal action as m approaches infinity. Our model includes the multinomial probit model of Myatt and Wallace (2003) [5] as a special case. We show that their formula describing the rates of decay of choice probabilities is incorrect, provide the correct formula, and use our large deviations analysis to provide intuition for the difference between the two.     

Does peer group size influence social preferences and risk taking?

This paper examines whether the ex post relative payoffs of peers as well as the size of the peer group impact an agent's willingness to take risks. For example, persons in a flood plain may be less likely to purchase flood insurance if their neighbors also refrain from purchasing. We generalize the Fehr‐Schmidt (1999) model to allow the intensity of the social preferences to vary with the size of the peer group. Our experiment tests whether subjects are more or less likely to choose a lottery over a fixed payment when others have been assigned either the same lottery or the fixed payment. Using both between and within subject designs, we find risk‐taking behaviour is not responsive to the risks faced by others regardless of the size of peer group.     

The robustness of robust implementation

We show that a mechanism that robustly implements optimal outcomes in a one-dimensional supermodular environment continues to robustly implement ε-optimal outcomes in all close-by environments. Robust implementation of ε-optimal outcomes is thus robust to small perturbations of the environment. This is in contrast to ex-post implementation which is not robust in this sense as only trivial social choice functions are ex-post implementable in generic environments.     

A new necessary condition for implementation in iteratively undominated strategies

We uncover a new necessary condition for implementation in iteratively undominated strategies by mechanisms that satisfy the “best element property” where for each agent, there exists a strategy profile that gives him the highest payoff in the mechanism. This class includes finite and regular mechanisms. We conclude that either the quasilinearity-like assumptions of available sufficiency results cannot be completely dispensed with or some mechanisms that do not satisfy the best element property must be employed. We term the condition “restricted deception-proofness.” It requires that, in environments with identical preferences, the social choice function be immune to all deceptions, making it then stronger than incentive compatibility. In some environments the conditions for (exact or approximate) implementation by mechanisms satisfying the best element property are more restrictive than previously thought.     

The optimal choice of central bank independence and conservatism under uncertainty

This paper examines the optimal monetary delegation arrangement of central bank independence and conservatism in the presence of uncertainty about the central bank’s output objective. We show that full independence is no longer optimal with uncertain central bank preferences, and that optimal delegation involves the choice of both independence and conservatism. Further, we find that the usual trade-off between independence and conservatism no longer necessarily holds. Consequently, high central bank independence may also require a high level of conservatism.     

Coordination and delay in global games

What is the effect of offering agents an option to delay their choices in a global coordination game? We address this question by considering a canonical binary action global game, and allowing players to delay their irreversible decisions. Those that delay have access to accurate private information at the second stage, but receive lower payoffs. We show that, as noise vanishes, as long as the benefit to taking the risky action early is greater than the benefit of taking the risky action late, the introduction of the option to delay reduces the incidence of coordination failure in equilibrium relative to the standard case where all agents must choose their actions at the same time. We outline the welfare implications of this finding, and probe the robustness of our results from a variety of angles.     

Welfare economics,risk and uncertainty

Social decisions in risky contexts raise a number of difficult questions, such as: (1) Should social decisions be more or less risk averse than the average person? (2) Should we try to avoid large catastrophes more than frequent but limited harms with similar expected impact? (3) Should social decisions be ambiguity averse or stick to the expected utility canon? This paper reviews the welfare economics of risk and uncertainty and examines possible answers to these questions, based on the pros and cons of utilitarianism, ex ante egalitarianism and ex post egalitarianism.     

Peer effects in medical school

Using data on the universe of students who graduated from US medical schools between 1996 and 1998, we examine whether the abilities and specialty preferences of a medical school class affect a student's academic achievement in medical school and his choice of specialty. We mitigate the selection problem by including school-specific fixed effects, and show that this method yields an upper bound on peer effects for our data. We estimate positive peer effects that disappear when school-specific fixed effects are added to control for the endogeneity of a peer group. We find no evidence that peer effects are stronger for blacks, that peer groups are formed along racial lines, or that students with relatively low ability benefit more from their peers than students with relatively high-ability. However, we do find some evidence that peer groups form along gender lines.     

Endogenous timing and income inequality in the voluntary provision of public goods: Theory and experiment

This study theoretically and experimentally investigates the effects of income inequality on donors' decisions regarding timing choices and contributions to public goods when contribution timing is endogenously chosen by contributors. To this end, we use the conventional voluntary provision models of Warr (1983) and Bergstrom, Blume and Varian (1986), with Cobb–Douglas preferences augmented with a two-stage game of Hamilton and Slutsky (1990). The following results were obtained and experimentally confirmed. First, when the distribution of income is extremely unequal, donors are indifferent between the simultaneous and sequential moves in the contribution game. Second, as income inequality is decreased, the simultaneous-move contribution game is likely to emerge because every donor prefers to act as a leader. Nevertheless, a higher-income donor may also prefer to act as a follower without specific social preferences and uncertainty regarding the quality of public goods. Third, most theoretical predictions regarding timing decisions are supported in our laboratory experiment, provided that the participants had enough time to learn the consequences of their timing choices.     

Does religious faith affect household financial market participation? Evidence from China

Based on the 2013 China Household Finance Survey data, this paper investigates the impact of religious faith on household financial market participation and portfolio choice. The results show that religious faith can significantly promote household financial market participation. Besides, religious faith can increase the proportion of risky assets held by households, including equities. We also find that the need for social interaction and human capital accumulation can significantly induce religious residents to participate in financial markets and hold risky assets. Overall, our results reveal how faith affects household finance activities in China.     

PERCEIVED INTENTIONALITY IN 2 × 2 EXPERIMENTAL GAMES

We test experimentally whether decisions in 2 × 2 games with mixed equilibria depend on the co‐player being nature or a human agent. Controlling for social preferences, we find differences in decisions in the chicken game and battle of the sexes but not for stag hunt and matching pennies. We attribute these to subjects' perception of the other's intentionality and disapproval avoidance in particular.     

社会互动与投资选择

个体的投资选择是否受到社会互动的影响?社会互动的作用机制是什么?采用2005年中国12城市投资者行为调查数据,本文发现,总体而言,社会互动推动了个体当前和未来期望对银行存款、外汇、股票、债券、期货、基金、借出、做生意、保险金、收藏品、房地产、理财产品、彩票等投资项目的参与。社会互动的积极作用主要是通过个体遵循参考群体成员的投资选择所体现的社会规范来实现的。此外,内生互动带来的感受交流和信息获得分别推动了个体当前对保险金和未来期望对债券的投资,而情景互动降低了个体未来参与股市的期望。     

Rational expectations equilibria of economies with local interactions

We consider general economies in which rational agents interact locally. The local aspect of the interactions is designed to represent in a simple abstract way social interactions, that is, socioeconomic environments in which markets do not mediate all of agents’ choices, which might be in part determined, for instance, by family, peer group, or ethnic group effects. We study static as well as dynamic infinite horizon economies; we allow for economies with incomplete information, and we consider jointly global and local interactions, to integrate e.g., global externalities and markets with peer and group effects. We provide conditions under which such economies have rational expectations equilibria. We illustrate the effects of local interactions when agents are rational by studying in detail the equilibrium properties of a simple economy with quadratic preferences which captures, in turn, local preferences for conformity, habit persistence, and preferences for status or adherence to aggregate norms of behavior.     

Modeling internal commitment mechanisms and self-control: A neuroeconomics approach to consumption–saving decisions

We provide a new model of consumption–saving decisions which explicitly allows for internal commitment mechanisms and self-control. Agents have the ability to invoke either automatic processes that are susceptible to the temptation of ‘over-consuming,’ or alternative control processes which require internal commitment but are immune to such temptations. Standard models in behavioral economics ignore such internal commitment mechanisms. We justify our model by showing that much of its construction is consistent with dynamic choice and cognitive control as they are understood in cognitive neuroscience.The dynamic consumption–saving behavior of an agent in the model is characterized by a simple consumption–saving goal and a cut-off rule for invoking control processes to inhibit automatic processes and implement the goal. We discuss empirical tests of our model with available individual consumption data and we suggest critical tests with brain-imaging and experimental data.