学术论文

情绪表达被网络新闻广泛地传播。现时在研究读者对网络新闻的看法时，主要聚焦语境线索对读者的推论和考量的影响；然而，愤怒、悲伤等分立情绪所扮演的角色却被忽视。 本文旨在填补相关研究领域的空隙，通过检视网络新闻所表达愤怒和悲伤的情绪，分析如何对读者造成影响。 利用情绪即社会信息（EASI）理论和评价倾向框架（ATF），我们发现网络新闻表达的愤怒情绪会降低其可信度。 但是，悲伤的情绪不会引起相同的效果。 研究另一个测试进一步发现，表达愤怒的情绪，可以解释为读者对作者认知心力的看法：读者认为，新闻标题表达愤怒的情绪，代表作者在撰写新闻时缺乏认知心力，令新闻可信度降低。 我们还展示了新闻可信度具有下游影响，可以影响各种社交媒体行为，包括阅读、喜欢、评论和分享。 本研究以网络新闻上的分立情绪（即愤怒、悲伤）为焦点，拓展了认知评估和人际影响层面的知识。 研究的结果具有实际意义，帮助社交媒体平台、新闻聚合平台和监管机构管理数字内容，防止假新闻传播。

In the standard herding model, privately informed individuals sequentially see prior actions and then act. An identical action herd eventually starts and public beliefs tend to “cascade sets” where social learning stops. What behaviour is socially efficient when actions ignore informational externalities? We characterize the outcome that maximizes the discounted sum of utilities. Our four key findings are: (a) Cascade sets shrink but do not vanish, and herding should occur but less readily as greater weight is attached to posterity. (b) An optimal mechanism rewards individuals mimicked by their successor. (c) Cascades cannot start after period one under a signal logconcavity condition. (d) Given this condition, efficient behaviour is contrarian, leaning against the myopically more popular actions in every period. We make two technical contributions: As value functions with learning are not smooth, we use monotone comparative statics under uncertainty to deduce optimal dynamic behaviour. We also adapt dynamic pivot mechanisms to Bayesian learning.

在视频行销研究中，我们重点关注了速度线索这一视频行销常用的优化手段，即行销管理者、广告设计者通常会通过改变视频广告中代言人的动作速度来试图影响消费者对产品的感知。我们发现，视频广告中应用慢动作技术反而会降低行销手段的说服力，并且该效应的心理与认知机制是消费者所产生的意图性感知（Perception of intentionality），即消费者认为代言人的慢速的代言行为不是自发而是 “故意的”。该研究同时采用了认知科学的眼动分析（Eye-tracking）方法印证了该结论。综上，该研究发展和完善了消费者视觉处理与心理机制的理论，为研究消费者在新媒体环境下的行为机制提供新的视角。

我们在无偏好设定的情况下引入风险纠缠的概念，以一并解释数据中的汇率波动性、周期性和货币风险溢价。风险纠缠对应了一部分不完备市场模型，当中对汇率的非扩散或非对数正态冲击并未能完全被资产回报所解释。当风险纠缠时，会出现多种定价一致的汇率，但它们都不等于随机贴现因数（SDFs）的比率或其预测。将汇率与SDF脱钩能让我们解释在国际金融中令人费解的主要外汇市场规律。

本文就市场对于经济关联公司的新闻所出现延迟价格反应提出了一个基于心理学的新解释。我们发现经济关联公司的股价收益预测，取决于其目前股价与52周最高股价之间有多接近。经济关联公司的新闻与公司股价是否接近其52周高位，部份解释了为何市场对于消费者、地理邻居、同业或外国行业的新闻反应较为迟缓。研究亦发现股票分析师会因公司股价接近52周高位，亦对关经济关联公司的新闻产生了延迟反应。这些发现直接证明了公司股价接近52周高位对于投资者信念更新过程的影响。

本文研究资本品进口和中间品进口对促进企业生产率增长的不同效果，并量化分析关税结构对发展中国家贸易自由化的重要性。团队经过审视大量中国制造企业的数据，证明相比中间品进口，资本品进口能更大的提升企业生产率。虽然两类进口都能即时提高进口企业的生产率，但唯独资本品进口能产生动态生产力效应。另一方面，我们发现资本品进口和研究开发有显著的协同效应和诱导效应：资本品进口不仅能和研究开发协同产生更大的生产率效应，而且更能诱导更多的研究开发。但未有证据证明中间品进口也能产生类似效果。团队还研究了中国因加入世界贸易组织而下调投入品进口关税对企业生产率的影响。我们发现，由此带来的生产率效应中，18%可以归结为关税结构的改变。

研究显示中国地方政府在能够识别债权人的情况下，会选择性地拖欠债务。本文透过分析地方政府债务全面的数据，发现地方政府会选择拖欠政治权力较弱的银行的债务。若一间银行相对于其他银行的政治权力减弱，会增加地方政府选择拖欠其债务的机率。这类选择性债务拖欠取决于银行对政客职位晋升的影响力。当这些地方政客职位较高，或与国家领导人有联系时，因为拖欠银行贷款对他们的晋升机会影响较小，故他们也会较少选择性地拖欠个别银行的债务。研究结果发现政治与金融两者的关系有助约束政府拖欠债务的情况。

In our target‐initiated theory of takeovers, a target approaches potential acquirers that privately know their standalone values and merger synergies, where higher synergy acquirers tend to have larger standalone values. Despite their information disadvantage, targets can extract all surplus when synergies and standalone values are concavely related by offering payment choices that are combinations of cash and equity. Targets exploit the reluctance of high‐valuation acquirers to cede equity claims, inducing them to bid more cash. When synergies and standalone values are not concavely related, sellers can gain by combining cash with securities that are more information‐sensitive than equities.

A common problem in econometrics, statistics, and machine learning is to estimate and make inference on functions that satisfy shape restrictions. For example, distribution functions are nondecreasing and range between zero and one, height growth charts are nondecreasing in age, and production functions are nondecreasing and quasi-concave in input quantities. We propose a method to enforce these restrictions ex post on generic unconstrained point and interval estimates of the target function by applying functional operators. The interval estimates could be either frequentist confidence bands or Bayesian credible regions. If an operator has reshaping, invariance, order-preserving, and distance-reducing properties, the shape-enforced point estimates are closer to the target function than the original point estimates and the shape-enforced interval estimates have greater coverage and shorter length than the original interval estimates. We show that these properties hold for six different operators that cover commonly used shape restrictions in practice: range, convexity, monotonicity, monotone convexity, quasi-convexity, and monotone quasi-convexity, with the latter two restrictions being of paramount importance. The main attractive property of the post-processing approach is that it works in conjunction with any generic initial point or interval estimate, obtained using any of parametric, semi-parametric or nonparametric learning methods, including recent methods that are able to exploit either smoothness, sparsity, or other forms of structured parsimony of target functions. The post-processed point and interval estimates automatically inherit and provably improve these properties in finite samples, while also enforcing qualitative shape restrictions brought by scientific reasoning. We illustrate the results with two empirical applications to the estimation of a height growth chart for infants in India and a production function for chemical firms in China.