基于消费者显著性偏好的双边平台转换成本和定价策略研究

针对消费者对转换成本和价格属性具有显著性偏好的实际情况，基于显著性理论对垄断双边平台企业的转换成本和定价策略问题进行了研究。研究发现：1)在显著性偏好非对称型市场上，对价格敏感的一方收取的价格最低，对高转换成本的一方收取的价格最高，而在显著性偏好对称型市场上，平台的最优价格位于非对称型市场之间，但是对价格敏感型市场收取的价格低于转换成本敏感型市场的价格。2)在高转换成本的市场，平台利润最低；低转换成本市场平台利润最高，而混合型情况的最优利润位于这两者之间。该研究结论说明平台企业应该采取措施来降低用户加入平台的转换成本，从而增加利润，这与现实的案例研究结论相吻合。     

The effect of sociodemographic (mis)match between interviewers and respondents on unit and item nonresponse in Belgium

Interviewer characteristics affect nonresponse and measurement errors in face-to-face surveys. Some studies have shown that mismatched sociodemographic characteristics – for example gender – affect people's behavior when interacting with an interviewer at the door and during the survey interview, resulting in more nonresponse. We investigate the effect of sociodemographic (mis)matching on nonresponse in two successive rounds of the European Social Survey in Belgium. As such, we replicate the analyses of the effect of (mis)matching gender and age on unit nonresponse on the one hand, and of gender, age and education level (mis)matching on item nonresponse on the other hand. Recurring effects of sociodemographic (mis)match are found for both unit and item nonresponse.     

Efficiency or Competition? A Structural Econometric Analysis of Canada's AWS Auction and the Set‐Aside Provision

In 2008, Industry Canada auctioned 105 MHz of spectrum to a group of bidders that included incumbents and potential new entrants into the Canadian mobile phone market, raising $4.25 billion. In an effort to promote new entry, 40 MHz of spectrum was set‐aside for new entrants. In order to estimate the implicit cost of the set‐aside provision, we estimate the parameters of the bidders' profit function via a maximum match estimator based on the notion of pairwise stability in matches. We find that all telecommunications firms valued both geographic complementarities across auction licenses as well as absolute spectrum. Under a reasonable alternative scenario, our results indicate that the set‐aside led to a total profit loss of approximately 10%.     

农村地区食品安全监管配套制度的完善与落实

自2009年《食品安全法》颁布至今,我国农村地区的食品安全事件依旧频发,《食品安全法》在农村地区的实施效果远不如城市。造成这种状况的原因除长期以来存在的城乡二元结构和农村居民自身生活习惯等问题外,更主要的是《食品安全法》作为一部在全国范围内统一实施的法律,其明显缺乏专门针对农村食品经营主体的监管配套制度,从而使该法在广大农村地区实施的过程中监管能力明显不足。据此,提出构建食品安全监管在农村地区的配套制度,加强技术监管和信息化管理以及充分发挥社会共治等建议。     

Quantifying the similarity of 2D images using edge pixels: an application to the forensic comparison of footwear impressions

We propose a novel method to quantify the similarity between an impression (Q) from an unknown source and a test impression (K) from a known source. Using the property of geometrical congruence in the impressions, the degree of correspondence is quantified using ideas from graph theory and maximum clique (MC). The algorithm uses the x and y coordinates of the edges in the images as the data. We focus on local areas in Q and the corresponding regions in K and extract features for comparison. Using pairs of images with known origin, we train a random forest to classify pairs into mates and non-mates. We collected impressions from 60 pairs of shoes of the same brand and model, worn over six months. Using a different set of very similar shoes, we evaluated the performance of the algorithm in terms of the accuracy with which it correctly classified images into source classes. Using classification error rates and ROC curves, we compare the proposed method to other algorithms in the literature and show that for these data, our method shows good classification performance relative to other methods. The algorithm can be implemented with the R package shoeprintr.     

Noninformative priors for the between-group variance in the unbalanced one-way random effects model with heterogeneous error variances

For the unbalanced one-way random effects model with heterogeneous error variances, we propose the non-informative priors for the between-group variance and develop the first- and second-order matching priors. It turns out that the second-order matching priors do not exist and the reference prior and Jeffreys prior do not satisfy a first-order matching criterion. We also show that the first-order matching prior meets the frequentist target coverage probabilities much better than the Jeffreys prior and reference prior through simulation study, and the Bayesian credible intervals based on the matching prior and reference prior give shorter intervals than the existing confidence intervals by examples.     

平台竞争、排他性协议与竞争瓶颈

在很多双边市场中,经常出现平台一边的用户与平台之间产生利益纠纷的现象,例如顺丰速运与菜鸟网络之间的纠纷等,本文从理论模型的角度研究了这种经济现象。文章通过将双边市场的用户分为视平台有差异和无差异两种类型,研究了平台如何掠夺视平台无差异的用户所有剩余的问题。研究发现,平台厂商有与视平台无差异的用户签订排他性协议的激励;无论签订排他性协议与否,这类用户都将被掠夺所有剩余,产生了所谓的"竞争瓶颈";排他性协议带来的福利效应并不明确,当平台的边际成本和交叉外部性参数较大时,排他性协议的签订能够提升社会总福利。     

工程车辆液力变矩器与发动机匹配的研究

对工程车辆中液力变矩器与发动机匹配的原则、评价指标和评价方法进行了分析研究，并结合工程车辆中使用工况比较复杂的装载机，进行了液力变矩器与发动机匹配评价的实例分析．     

“言文一致”与方言小说——清末小说中的“方言”问题

与“言文一致”、“小说界革命”的思潮密切相联系,晚清对用方言写小说形成一个理论自觉,也出现一批方言小说,其中以吴语小说和京语小说最具代表,可谓别开生面。但小说中大量运用方言来模拟口语的逻辑与小说“开民智”要求的普及性,以及小说语言的艺术性形成矛盾。重视小说艺术性的小说家就提出“另为一种言语”和“另造一种通行文字”的观点,这种兼顾口语化、普泛性和艺术性的白话书面语革新,才符合“官话一国语”建构的路径,为小说语言的由俗变雅提供了可能,也修正了方言小说的弊端,但这一理论真正的实现则在五四时期。     

初婚解体风险变化趋势及其影响因素——基于CFPS2010数据的分析

基于中国家庭追踪调查数据(CFPS2010),分析中国初婚解体风险变化趋势及其影响因素。结果表明:随时间推移,初婚解体风险总体呈现上升趋势,其对城市的影响超过了农村,对女性的影响超过了男性;初婚年龄与初婚解体风险呈现轻微的U型关系,主要是由早婚或晚婚的婚姻异质性所引起;婚姻异质性对初婚解体风险的作用受择偶梯度的影响,"男高女低"婚姻模式的初婚离婚风险远远小于"女高男低"模式;在家庭因素的影响中,生育孩子有利于降低初婚离婚风险,而与父母同住及婚前同居则显著增加了初婚离婚风险。