Migration, risk and livelihoods: A Chinese case

China has turned from a 'low risk' to a 'high risk' society since the start of the market reforms in the late 1970s. Market, while bringing diverse livelihood opportunities to rural people, has simultaneously distributed risks, and the exposure and vulnerability to them unequally among different social groups. This paper attempts to apply the risk concept to the study of one of the most socially disadvantaged groups in China, namely rural-urban migrants, through analysing the narratives of members of a migratory family of the Hui Muslim national minority from the Qinghai-Tibet Plateau, who run a business in the northern city of Tianjin. Drawing on ethnographic fieldwork, the research adopts an actor-oriented perspective combined with qualitative longitudinal research methodology (or 'extended case method') to delineate a livelihood trajectory of this family, and explore the relationships between livelihood, risk, social networks, agency and public policy interventions. --rural-urban migration,risk,contingency,uncertainty,livelihood,social networks,agency,social security,translocality,longitudinal research,narrative,extended case method,China

The political economy of rural development in China: reflections on current rural policy

The paper examines some of the main political economy dynamics of the policy initiatives on rural development that have been taken since 2003, and provides an overview of the main issues that they are addressing. The paper first outlines the major agrarian problems that have emerged over the recent decade and more, indicating their main political-economy causations, and then systematically analyses the prospects of the new policy initiatives to deal with them. Among the new policies the initiatives to reorganise the finance system through a reform of the roles of the county and a development of town and township governments to become points of delivery of public goods and social services are highlighted as particularly potent. Further importance is associated with reforms that strengthen the role of rural residents as citizens. The impact of the Chinese government's economic stimulus package in response to the ongoing global financial crisis is yet to become visible, but it is clear that the changes must be backed up with very substantial political and financial commitments. --rural policy,political economy,rural-urban relations

Research on Intrusion Detection of Database based on Rough Set

AbstractIn this article, we apply the rough set theory to database intrusion detection and monitor the data in real time with intrusion detection. While theory based on rough set will judge the attacks according to the rules and respond to the sample data of intrusion detection after preprocessing them

Completely Precontinuous Posets

AbstractIn this paper, concepts of strongly way below relations, completely precontinuous posets, coprimes and Heyting posets are introduced. The main results are: (1) The strongly way below relations of completely precontinuous posets have the interpolation property; (2) A poset P is a completely precontinuous poset iff its normal completion is a completely distributive lattice; (3) An ω-chain complete P is completely precontinuous iff P and Pop are precontinuous and its normal completion is distributive iff P is precontinuous and has enough coprimes; (4) A poset P is completely precontinuous iff the strongly way below relation is the smallest approximating auxiliary relation on P iff P is a Heyting poset and there is a smallest approximating auxiliary relation on P. Finally, given a poset P and an auxiliary relation on P, we characterize those join-dense subsets of P whose strongly way-below relation agrees with the given auxiliary relation

Price Cycles in Online Advertising Auctions

Paid placement in search engines has become one of the most successful and rapidly growing sectors of the online advertising industry. The innovative use of auctions to sell keyword-related advertisement positions is perhaps the most important factor driving the success of this market. There has been no systematic analysis, however, of the advertisers’ strategies to bid for ranks in a dynamic environment, where each bidder’s bid can be updated and observed by the competitors in real time. We capture this dynamic setting using a Markov process and identify the Markov perfect equilibrium. We find that in such a dynamic environment, bidders’ bidding strategies follow a cyclical pattern (Edgeworth cycle) similar to that conjectured by Edgeworth (1925) in a totally different context. A new data set that contains a detailed bidding history of all advertisers for sample keywords in a leading search engine makes it possible for us to study the real-world behavior of bidders. We propose an empirical framework based on maximum likelihood estimation of latent Markov state switching to confirm the theory. We also discuss the theoretical and practical significance of finding such cycles in an online market place

Slicing the Gordian Knot: A Novel Mechanism for Providing Innovation Incentives for Digital Goods

Digital goods can be reproduced without cost. Thus a price of zero would be economically efficient in terms of eliminating deadweight loss. Unfortunately, zero revenues would also eliminate the economic incentives for creating such goods in the first place. We develop a novel mechanism which solves this dilemma by decoupling the price of digital goods from the payments to innovators while maintaining budget balance and incentive compatibility. Specifically, by selling digital goods via large bundles, the marginal price for consuming an additional good can be made zero for most consumers. Thus efficiency is enhanced. Meanwhile, we show how statistical sampling can be combined with tiered coupons to reveal the individual demands for each of the component goods in such a bundle. This makes it possible to provide accurate payments to creators which in turn spur further innovation. In our analysis of the proposed mechanism, we find that it can operate with an efficiency loss of less than 0.1 percent of the efficiency loss of the traditional price-based system. Innovation incentives in our mechanism are, of course, dramatically improved relative to the zero-price approach often favored by content consumers. However, it is surprising to find that the innovation incentives are also substantially better than those provided by the traditional system based on excludability and monopoly pricing which is often favored by content owners. The technology and legal framework for our proposed mechanism already exist and portions of it have already been implemented, although not in any coordinated fashion

The Lord Of The Ratings: Is A Movie\u27s Fate is Influenced by Reviews?

Third-party reviews play an important role in many contexts in which tangible attributes are insufficient to enable consumers to evaluate products or services. In this paper, we examine the impact of professional and amateur reviews on the box office performance of movies. Using a simple diffusion model, we establish an econometrics framework to control for the interaction between the unobservable quality of movies and a word-of-mouth diffusion process and thereby estimate the residual impact of online amateur reviews on demand. The results indicate the significant influence of the valence measure (star ratings) of online reviews, but their volume measure (propensity to write reviews) is not significant once we control for quality. Furthermore, the analysis suggests that the variance measure (disagreement) of reviews does not play a significant role in the early weeks after a movie opening. The estimated influence of the valence measure implies that a one-point increase in the valence can be associated with a 4–10% increase in box office revenues

Tapping into the pulse of the market : essays on marketing implications of information flows

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, 2006.Includes bibliographical references (p. 113-115).As the Internet continues to penetrate consumer households, online marketing is getting increasingly important for firms. By adapting to online strategies, firms are blessed (or doomed) with a plethora of new business models. The information flows created in the process poses both opportunities and challenges for marketers. On one hand, information flows captured online are usually easier to be stored and processed, thus empowering firms to be better informed about the consumers or the market itself. On the other hand, how to use the information flows to make the correct managerial decisions is still a challenging task for managers and academics alike. My dissertation studies the marketing implications of these information flows. Broad as the research question is, my dissertation focuses on specific market settings. I adopt both analytical and empirical methodologies to study information flows in these markets. Overall, this dissertation concludes that information flows can engender new market mechanisms, can provide valuable information of unobservable market forces, and can be created to improve social welfare. Essay 1: Innovation Incentives for Information Goods. Digital goods can be reproduced costlessly.(cont.) Thus a price of zero would be economically-efficient for consumers. However, zero revenues would eliminate the economic incentives for creating such goods in the first place. We develop a novel mechanism which tries to solve this dilemma by decoupling the price of digital goods from the payments to innovators while maintaining budget balance and incentive compatibility. Specifically, by selling digital goods via large bundles the marginal price for consuming an additional good can be made zero for most consumers. Thus efficiency is enhanced. Meanwhile, we show how statistical sampling can be combined with tiered coupons to reveal the individual demands for each of the component goods in such a bundle. This makes it possible to provide accurate payments to creators which spurs further innovation. In our analysis of the proposed mechanism, we find that it can operate with an efficiency loss of less than 0.1. Essay 2: Edgeworth Cycles in Keyword Auctions. Search engines make a profit by auctioning off advertisement positions through keyword auctions. I examine the strategies taken by the advertisers.(cont.) A game theoretical model suggests that the equilibrium bids should follow a cyclical pattern- "escalating" phases interconnected by "collapsing" phases - similar to a pattern of "Edgeworth Cycles" that was suggested by Edgeworth (1925) in a different context. I empirically test the validity of the theory. With an empirical framework based on maximum likelihood estimation of latent Markov state switching, I show that Edgeworth price cycles exist in this market. I further examine, on the individual bidder level, how strategic these bidders are. My results suggest that some bidders in this market adjust their bids according to Edgeworth predictions, while others not. Finally, I discuss the important implications of finding such cycles. Essay 3: The Lord of the Ratings. Third-party reviews play an important role in many contexts in which tangible attributes are insufficient to enable consumers to evaluate products or services. In this paper, I examine the impact of professional and amateur reviews on the box office performance of movies. I first show evidence to suggest that the generally accepted result of "professional critics as predictors of movie performance" may no longer be true.(cont.) Then, with a simple diffusion model, I establish an econometrics framework to control for the interaction between the unobservable quality of movies and the word-of-mouth diffusion process, and thereby estimate the residual impact of online amateur reviews on demand. The results indicate the significant influence of the valence measure (ratings) of online reviews, but their volume measure (propensity to write reviews) is not significant once I control for quality. Furthermore, the analysis suggests that the variance measure (disagreement) of reviews does not play a significant role in the early weeks after a movie's opening. The estimated influence of the valence measure implies that a one-point increase in the valence can be associated with a 4-10% increase in box office revenues.by Xiaoquan (Michael) Zhang.Ph.D

The Influence of Online Consumer Reviews on the Demand for Experience Goods: The Case of Video Games

We examine the effect of online consumer reviews on the sales of video games. An inherent problem in measuring the influence of reviews on demand is that products receiving good reviews tend to be of high quality, and it is difficult to determine whether the review or the quality is responsible for the high demand. To circumvent this problem, we consider video games that are developed for both PlayStation 2 and Xbox and take a differences-in-differences approach to a structural model of game demand. Our results indicate that online consumer reviews have a significant influence on the sales of the video games. On average, one point increase in the average rating is associated with 4% increase in game sales. Negative ratings have a larger impact than positive ratings. In addition, we find that online reviews are more influential for less popular games. These results suggest the importance of managing online word of mouth for firms, especially for their less popular products