浅谈基于大数据背景下的数字经济发展——以数字电网为例

我们已经进入了一个全新的大数据信息化时代,充满了更多的机遇与挑战。大数据及数字经济的出现极大程度地改变了传统技术及工作思维的方式。数字经济是继工业和农业之后的又一大经济形态,为社会的经济增长提供了新的动力。通过分析电网行业传统的科学技术及作业方式,论文简要阐述了基于大数据信息化发展下电网的影响,并认为信息化技术的发展对于数字经济有着至关重要的影响及重要性。最后论文讨论了数字经济发展存在的问题及方向。     

A picture is worth a thousand words: The role of a cover photograph on a travel agency’s online identity

Online travel agencies (OTAs) allow lodging businesses to select one cover photograph to represent itself on the OTA site. The cover photograph plays a crucial role for attracting customers’ attention from among alternatives, and lure viewers to view the webpage with detailed information. The present study investigates how the content of a business’ cover photograph on OTAs’ sites influences customers’ behavior when searching for information. The content of a cover photograph may fall within five categories according to attributes: façade, type of place, room amenities, scenery, and property amenities. Only façade and property amenities have positive impacts on customers’ viewing times of the webpages with the detailed information of businesses. In contrast, scenery has a negative influence on customers’ viewing times. The results of the study contribute, theoretically and methodologically, to OTAs’ knowledge base and can assist practitioners’ identification of effective cover photographs.     

跳频信号的归一化多普勒频差最大似然估计

针对双站定位涉及的跳频信号多普勒频差估计问题，提出了归一化的频差最大似然估计算法，利用两个定位站接收到的跳频脉冲串信号，构建一个关于基准跳频频率多普勒频差的似然函数，通过网格搜索得到使似然函数最大的多普勒频差估计，既解决了跳频信号在不同跳频频率上多普勒频差不一致的问题，又充分利用在不同频率的脉冲串信号提高了多普勒频差估计精度。通过仿真对算法的性能进行了评估，结果表明，与基于子空间的算法比较，在脉冲数达到240个时，所提算法执行效率提升30%以上。     

Welfare Cost of Fluctuations When Labor Market Search Interacts with Financial Frictions

We study the welfare costs of business cycles in a search and matching model with financial frictions. The model replicates the volatility on labor and financial markets. Business cycle costs are sizable. Indeed, the interactions between labor market and financial frictions magnify the impact of shocks via (i) a credit multiplier effect and (ii) an endogenous wage rigidity inherent to financial frictions. In addition, in a nonlinear framework, large welfare costs of fluctuations are explained by the high average unemployment and the low job finding rates with respect to their deterministic steady‐state values.     

The airfare pricing and seat allocation problem in full-service carriers and subsidiary low-cost carriers

This study investigates the competitive market situation in the air transport industry considering full-service carriers (FSC), subsidiary low-cost carriers (LCC) and rival LCCs on the flight-leg level while subsidiary LCCs are established by FSCs against rival LCCs to keep the market share and to make more profit. It is assumed that the demand of economy class for each airline follows a known distribution, and the mean value of that distribution is a function of its airfare and the airfare differences with other airlines. In addition, no-shows and cancellations are introduced to reflect a real situation. Based on this situation, a mathematical model is developed to derive efficient airfare pricing and seat allocation for each airline for maximizing the profit sum of both FSCs and subsidiary LCCs using a repeated game. A repeated game model integrated with a Tabu search algorithm and an EMSR based heuristic is suggested to deal with the proposed repeated game. A numerical example is provided to validate the model and solution procedure with hypothetical system parameter values under two kinds of market situations that show before and after the emergence of subsidiary LCCs.     

Investor Pessimism and the German Stock Market: Exploring Google Search Queries

We analyze the relationship of retail investor sentiment and the German stock market by introducing four distinct investor pessimism indices (IPIs) based on selected aggregate Google search queries. We assess the predictive power of weekly changes in sentiment captured by the IPIs for contemporaneous and future DAX returns, volatility and trading volume. The indices are found to have individually varying, but overall remarkably high explanatory power. An increase in retail investor pessimism is accompanied by decreasing contemporaneous market returns and an increase in volatility and trading volume. Future returns tend to increase while future volatility and trading volume decrease. The outcome is in line with the conjecture of correction effects. Overall, the results are well in line with modern investor sentiment theory.     

Sibling gender and wage differences

Family influences on economic performance are investigated. In particular, sibship sex composition is related to hourly wages using data from the National Longitudinal Survey of Youth 1979. The wages of men are increasing in the proportion of siblings who are brothers, but the wages of women are insensitive to sibling gender. Nonwage outcomes are generally unaffected. Contrasts by age structure and demographic group are also presented. The analysis addresses econometric challenges like the endogeneity of fertility and selection into the workforce. In addition, mechanisms such as labour market interactions, human capital investment and role model effects are documented. A questionnaire on job search indicates a same-gender bias in the use of brothers and sisters in obtaining employment. Developmental and psychological assessments suggest that brothers may be associated with worse childhood home environments and more traditional family attitudes among women. The findings are policy relevant and contribute to an understanding of gender differences and earnings inequality.     

Should sequels differ from original movies in pre-launch advertising schedule? Lessons from consumers' online search activity

Sequels have become a profitable strategy in the U.S. motion picture industry because of their strong name recognition. However, while the established positioning of a sequel may help insulate it from competing firms' advertising messages, its familiarity may cause moviegoers to be more easily satiated with advertising from the sequel. Therefore, this study examines how sequels differ from original concept movies in terms of their ad effectiveness. We focus our analysis on pre-launch periods, given these periods' importance in shaping the financial outcomes of motion pictures. We consider the weekly online search volume of a movie as a measure of consumer interest in it, and thus as an intermediate response to pre-launch advertising. We then develop a model that assumes ad effectiveness can decline, due to copy and repetition wearout, and increase, due to forgetting, over time. We find that copy wearout is greater for original movies, while repetition wearout and forgetting are greater for sequels. These findings suggest that sequels should allocate more in early pre-launch periods and less immediately before release, relative to originals, to maximize pre-launch consumer interest.     

The interaction between reputation and information search: Evidence of information avoidance and confirmation bias

This paper investigates how the valence of reputation affects the information search, and how the outcome of the search can result in a reevaluation of reputation. The protocol uses a digital version of the Information Display Board (IDB) to examine the dynamics of information search and reputation building. A sample of 1811 respondents was asked about their perceptions of the reputation of specific performing arts events, pre- and post-information search. The findings provide evidence of a confirmation bias (between positive information and the information search), and support information avoidance theories. Specifically, our results show that prior reputation only affected the online information search for consumers with no opinion, or with a positive opinion of a show's reputation. Furthermore, the information search only modifies reputation when consumers have no prior opinion.     

Search within or beyond the industrial cluster? The effect of perceived competition and knowledge base tacitness on strategic location choices of external knowledge search

ABSTRACT

From a knowledge-based perspective, this paper highlights the need for a framework linking perceived competition of the industry and firms’ strategic location choices of external knowledge search and examines whether the perceived competition increases the propensity of cluster firms to search more widely from extra-cluster knowledge sources than intra-cluster knowledge sources. Furthermore, we emphasise that cluster firms with varying degrees of tacitness in their knowledge base might respond to such competition differently when conducting external knowledge search activities. Using a sample of 310 cluster firms in the Zhejiang Province of China, we find that the cluster firm would increase the propensity for more geographic boundary-spanning search relative to local search while under the pressure of competition. Moreover, the positive relationship between perceived competition and the propensity towards geographic knowledge search is weaker when the tacitness of the cluster firm’s knowledge base is higher. The findings contribute to the understanding of the relationship between competition and the choice of location strategies in external knowledge search.