2021年9月，高等经济研究院助理教授赵书辰的两篇论文被经济学领域权威期刊Journal of Economic Behavior & Organization相继接收发表。
赵书辰与加利福尼亚大学圣克鲁兹分校经济学院教授Daniel Friedman合作的论文"When Are Mixed Equilibria Relevant?"研究混合策略均衡的实证关联。该论文采用实验室实验，研究了两个具有唯一纳什均衡和唯一最大化最小策略均衡的完全混合策略博弈。变量环境为被试匹配方式（一对一或组对组）、时间的连续性及参与者的策略空间。实验证明纳什均衡在组对组匹配中的预测结果最好，同时在所有环境中优于最大化最小策略均衡；但是在大多数一对一匹配中，均匀的混合策略预测结果优于纳什均衡；参与者的动态路径更符合基于后悔的学习模型。实验结果为实证社会科学、生物学及博弈论理论提供了有力参考。
赵书辰作为独立作者的论文"Taking Turns in Continuous Time"在实验室环境下研究了连续时间环境对重复性别战博弈的影响。在传统离散时间下，参与者通常在两个纯策略纳什均衡间交替进行协调。在连续时间下，参与者可以更快地做出反应，但需要面临更大的策略空间，并且缺乏协调工具。为了分离不同因素对协调行为的影响，实验添加了另一种混合时间环境，即被试在连续时间下行动的同时收到与离散时间环境相同的自然信号。实验发现，混合时间大大促进了协调和交替行为。同时，在连续时间下，纳什均衡中处于劣势的参与者倾向于首先移动到其他纳什均衡，而整体的动态交替是异步而非同步进行。实验结果表明人们应当在现实的协调问题中主动寻找能够辅助协调的外生信号，同时证明了现实中存在异步交替行为。
Assistant Professor Shuchen ZHAO's Two Papers Accepted for Publication in Journal of Economic Behavior & Organization
October 21, 2021
Shuchen ZHAO, IAER Assistant Professor, had his two papers accepted for publication in Journal of Economic Behavior & Organization in September, 2021.
Entitled "When Are Mixed Equilibria Relevant?", the paper was co-authored with Daniel Friedman, Professor of Economics at the University of California Santa Cruz. It studies the empirical relevance of mixed strategy equilibria. In particular, the paper studies in the laboratory two games, each with a unique Nash equilibrium and a unique (and distinct) Maximin equilibrium in completely mixed strategies. Treatment variables include matching protocols (pairwise random vs population mean matching), whether time is discrete or continuous, and whether players can specify explicit mixtures or only pure strategy realizations. Nash mixes predict observed behavior relatively well in population mean matching treatments, and predict better than Maximin in all treatments. However, in most random pairwise treatments, uniform mixes predict better than Nash. Regret-based and sign preserving dynamics capture regularities across all treatments. The results help guide work for applied social scientist, biologists, and theorists.
Entitled "Taking Turns in Continuous Time", it examines the impact of continuous-time interactions on the dynamics of repeated battle of the sexes games with laboratory experiments. In discrete time, players often coordinate by alternating each period between the two pure Nash equilibria. In continuous time, players can respond more quickly but must contend with a very rich strategy space and with the lack of a natural coordination device. The experiment also examines a new hybrid-time environment that runs in continuous time but offers a discrete payoff-irrelevant signal. The results suggest that the hybrid signal device greatly facilitates both coordination and alternation. Players generally tend to alternate asynchronously in continuous time, and the transitions between pure Nash equilibria are mainly driven by the "disadvantaged player". The results indicate that people should try to pursue some signals to coordinate and point out the phenomenon of asynchronous turn taking.