On the existence of the ex post symmetric random entry model

This paper studies symmetry among countably infinitely many agents who randomly enter into a stochastic process, one for each period. Upon entry, they observe only the current period signal and try to draw inference about the underlying state governing the stochastic process. We show that there exist random entry models under which agents are ex post symmetric. That is, all agents have identical posterior belief about the underlying states, although they are not ex ante symmetric. The form of the posterior belief is uniquely pinned down by ex post symmetry and a stationarity condition. Our results provide a common prior foundation for the model studied in Liu and Skrzypacz (2014).     

创业企业何以提高创新绩效——基于创业学习与商业模式创新协同联动视角的QCA方法

以150个创业企业为样本，基于创业学习和商业模式创新理论，运用模糊集定性比较分析方法（fsQCA），探究经验学习、认知学习、新颖型商业模式创新和效率型商业模式创新对创新绩效的影响路径及机制。研究发现，存在新颖型商业模式创新等4条创新绩效产出关键路径；相较于效率型商业模式创新，新颖型商业模式创新在关键路径中更容易提高创新绩效；利用QCA方法证实了影响创业企业创新绩效的组态内部各要素之间的替代性。结论丰富了创新绩效产出内部机制，可为创业企业提高创新绩效提供指导和借鉴。     

Performance and learning in an ambiguous environment: A study of cryptocurrency traders

We investigate the performance and learning ability of traders in an environment governed by ambiguity, such as the cryptocurrency market. Using a profit decomposition methodology, we find significant cross-sectional and temporal heterogeneity in performance. Traders do not learn to progressively increase the magnitude of returns; however, they are able to improve on their ability to realise profits as a mechanism of adaptation to survive through ambiguity. This adaptation increases as traders progress through their career. Moreover, we find evidence in support of the gambler’s fallacy. We argue that learning in ambiguous environments has limitations, allowing traders primarily to survive.     

The contractionary effects of tax shocks on productivity: An empirical and theoretical analysis

I analyze the effects of tax policy changes on US Total Factor Productivity. VAR estimates show that permanent and exogenous tax increases have strong, permanent, and negative effects on TFP which represent about 80% of change in output following the tax increase. I then build a DSGE model which has learning-by-doing and endogenous TFP evolution. The benchmark model is able to replicate the empirical impulse responses. However, when I calibrate the model as in the literature, the effect of taxes on TFP is substantially less elastic than in the data. I argue that this divergence may arise because tax changes labeled as exogenous can give spurious results or because of a mis-specified model.     

Creating competitive advantage: Linking perspectives of organization learning,innovation behavior and intellectual capital

Drawing on learning theories and the intellectual capital (IC) theory, organizational learning research has discussed the benefits of searching for market opportunities and maintaining a competitive advantage in dynamic environments. To explain organizational performance and survival, the previous literature has focused mainly on what organizations do, but it has failed to address how and what they should do. This study argues that if hotel management is open-minded about exploratory and exploitative learning, it can open the door to capturing opportunity and competitive advantage through increased innovation behavior and human capital accumulation. Further, IC theory has also confirmed that social capital and relational capital will strengthen the relationship between innovation behavior and human capital. This study analyzes data from 595 hotel managers and finds strong support for the proposed hypotheses.     

Nonparametric learning rules from bandit experiments: The eyes have it!

How do people learn? We assess, in a model-free manner, subjectsʼ belief dynamics in a two-armed bandit learning experiment. A novel feature of our approach is to supplement the choice and reward data with subjectsʼ eye movements during the experiment to pin down estimates of subjectsʼ beliefs. Estimates show that subjects are more reluctant to “update down” following unsuccessful choices, than “update up” following successful choices. The profits from following the estimated learning and decision rules are smaller (by about 25% of average earnings by subjects in this experiment) than what would be obtained from a fully-rational Bayesian learning model, but comparable to the profits from alternative non-Bayesian learning models, including reinforcement learning and a simple “win-stay” choice heuristic.     

Passive learning: a critique by example

In models of learning by experimentation that exhibit signal dependence, a benchmark using a passive learner has been proposed. The use of this benchmark is flawed – first, passive learning does not disentangle the effects of knowing that beliefs, as well as other state variables, might change, and we address this issue directly by introducing a naïve learner. Secondly, and more tellingly, passive learning does not do what it is supposed to do, namely help measure the gains from active experimentation; the naïve learner enables us to illustrate this point in the context of a particular example.     

二语词汇习得过程研究

词汇是二语学习的一项重要内容。学习者在二语词汇学习过程中必然会受到母语学习策略、母语认知和母语思维的影响。在词汇学习过程中,二语学习者要逐步减少对母语的依赖,逐渐适应二语词与概念的直接对应复习并运用所学词汇,对词汇信息进行深入全面的加工,培养二语词汇能力。     

外部研发合作广度与新产品开发绩效：一个有调节的中介模型

基于企业外部合作伙伴分布广泛的特点,从外部研发合作广度的两个维度（市场广度和研究广度）出发,选取2010—2018年160家中国制造业上市企业数据,运用多元回归分析法探讨外部研发合作广度对企业新产品开发绩效的影响。结果表明,外部研发合作的市场广度和研究广度正向影响新产品开发绩效,其中,研究广度的作用更为显著;网络学习在外部研发合作广度对新产品开发绩效的影响机制中存在部分中介作用;知识库同质性正向调节外部研发合作广度与网络学习的关系。结论丰富了新产品开发绩效前因变量研究,对企业制定外部研发合作战略,提升新产品开发绩效具有重要管理启示。