Mining History of Gamification Towards Finding Expertise in Question and Answering Communities: Experience and Practice with Stack Exchange

Recently, an online Q&A tool has become an essential part of individual communities and organizations of experts on specific topics. Using the answers to questions about specific topics will help such communities work more efficiently in their fields. Currently, Q&A online communities are adopting gamification to engage users by granting awards to successful users. In this paper, we investigate how to mine award achievement histories to find expertise. We propose the use of sequence analysis and clustering techniques. Specifically, we study the history of Stack Exchange, a large Q&A community that employs gamification. To the best of our knowledge, this is the first study of using award achievement history to find expertise in Q&A communities.     

The optimal exchange rate regime for a small country

This paper examines the welfare comparisons between a freely floating, a managed floating, and a pegged exchange rate regime. We compare the expected loss under these regimes by modifying and generalizing Hamada’s (2002) model to accommodate intervention policy. We consider the de jure and de facto classifications, where the former is defined by the officially stated intentions of the monetary authorities, while the latter is based on the actually observed behavior of the nominal exchange rate. We first examine the exchange rate regimes from the central bank’s policy stance and the actual exchange rate policy. Next we assume that the regime which the private sector perceives according to an official announcement may be different from the one adopted actually by the central bank. We examine nine combinations of the de jure and de facto regimes. We interpret that, whenever they are different, there is informational friction between the central bank and the private sector. We show that the welfare level of a small country under freely floating is no less than that under other regimes, and that with some restrictive conditions, the de facto pegged or de facto managed floating is close to freely floating. This partly explains “Fear of floating” and “Fear of pegging”.     

Toward better Japan-Europe economic relations

Present economic relations between Japan and Europe are marred by misunderstanding and ignorance of one another's positions, Mr. Ichikawa stresses here. Neither side has anything to gain from the continuance of this situation: a new phase—one of understanding and cooperation—must be begun. *** DIRECT SUPPORT *** A02GP021 00002     

Sustainability of Monetary-cum-Exchange Rate Policy in China

This paper theoretically considers the long-run sustainability of China’s monetary-cum-exchange rate policy under the impossible trinity. Two different models are examined: One sterilizes current net foreign assets (NFAs) and the other focuses on NFAs realized in the previous period. Under the de facto opening of financial flows, sterilization yields a negative risk premium in uncovered interest parity (UIP) that triggers a feedback increase among capital inflows. Here, stability depends on the magnitudes and the combination of structural and policy parameters. It is shown that if current capital inflows are sterilized, the monetary-cum-exchange rate policy in China offers a sustainable solution for exchange rates that are relatively stringently managed. However, such a solution can be obtained for relatively flexible or moderately managed rates if sterilization policy is implemented on the previous period’s inflows.     

Cordon Pricing and Land‐Use Regulation

This study explores the simultaneous imposition of cordon pricing and land‐use regulations in a continuous and closed monocentric city with homogeneous households. Results reveal the optimal level of a single cordon toll and its location and the optimal floor area ratio (FAR) regulation, clarifying what distortions remain in the existence of cordon pricing and FAR regulation. Among other results, this paper shows that, with an optimal cordon toll, FAR regulation should alternate between a minimum and a maximum regulation, both inside and outside the cordon line.     

Social Network Rebuilder: A Tool to Estimate a Social Network of Financial Crisis Propagation

The objective of this paper is to find a new method to estimate real social networks based on observed data collected by questionnaire surveys. Studies on social networks have been increasing in order to analyze social phenomena from a micro viewpoint. Most social phenomena can be explained by micro-level interactions among people. Spread of rumor and pandemics are typical example of micro interaction? However, there has not been much work on an analysis of real social networks based on observed data. This study tries to establish a methodology that exploits a genetic algorithm to rebuild a social network based on the data observed indirectly from real social networks. This paper introduces our proposed method, which allows us to rebuild a social network to some extent from degree distributions of a target real social network.     

Congestible communications networks and international trade

We build a two-country model of monopolistic competition with communications networks. A communications network is characterized by (1) the existence of large fixed costs of network provision, and (2) the presence of congestion. It is demonstrated that both the size of a country and the relative magnitude of the congestion effect determine its comparative advantage: if the congestion effect (resp., the cost-sharing effect) prevails universally, a comparative advantage in the goods that require communications is held by the smaller (resp., larger) of the two countries. JEL Classification: D43, F12
Réseaux de communication, congestion et commerce international. Ce mémoire présente un modèle de concurrence monopolistique à deux pays avec des réseaux de communication. Un réseau de communication est caractérisé par (1) l'existence de coûts fixes importants pour la mise en place du réseau et (2) la présence de congestion. On montre que la taille du pays et la magnitude relative de la congestion déterminent l'avantage comparatif : si l'effet de congestion (ou respectivement l'effet de partage des coûts) prévaut, un avantage comparatif dans les biens qui demandent plus de communication est détenu par le plus grand (respectivement le plus petit) des deux pays.