Kentaro Fukumoto

小学校6年生だったお姉ちゃんの君は、卒業直前に級友との思い出を深めるはずだった最後の1カ月が、いきなり消えてしまった。中学校に上がっても入学式はなく、新たな同級生にも会えなかった。妹の君も、家で勉強するための教材も大して配られなかったから暇…

Do candidates garner more votes simply because their names are better recognized? To answer this question, we use elections to the Japanese House of Councillors as a natural experiment. Members are elected in national and local-level districts. To isolate the effect of name recognition on vote choice, we compare the vote shares of national district candidates in high-name-recognition prefectures-which we define as prefectures in which a national candidate shares the same surname as a local district candidate-and the other low-name-recognition prefectures. Our research design addresses internal and external validity problems from which previous studies suffer. We find that national candidates obtain 69% larger vote shares in high-as opposed to low-name-recognition prefectures. This result holds when controlling for idiosyncratic characteristics of national candidates and prefecture-specific surname popularity.

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Although numerous get-out-the-vote field experiments have identified the effects of particular mobilization tactics (e.g., canvassing, phone calls, direct mails) on voter turnout, we do not yet have a full understanding of the causal effect of overall mobilization. We study this by leveraging a natural experiment in Japan, in which the timing of a municipal election is as-if randomly assigned. The results show that almost concurrently held municipal elections boost these municipalities' voter turnout in prefectural elections by one to two percentage points. We argue that some unique settings in Japan allow us not only to mitigate omitted variable bias but also to attribute the estimated effect only to mobilization, rather than the effects of cost sharing and psychological stimulus. (C) 2016 Elsevier Ltd. All rights reserved.

This study discusses a downside of electoral pressure. As elections approach, legislators reduce their effort in legislative activities, albeit while increasing their efficiency. To show this, we propose a new, natural experimental design exploiting staggered legislative election calendars to identify the effect of approaching elections. Two-way natural blocking improves the balance of pretreatments and an instrumental variable approach addresses noncompliance by retirees. Our analysis of the Japanese House of Councillors demonstrates that legislators up for election show up in the chamber less often than those not facing election; however, when they do show up and speak, they tend to speak longer.

In this research, we propose a new biclustering method for extracting communities from binary matrices which represent a binary relation. A binary relation can be represented as a bipartite graph or a binary matrix. Many effective clustering methods for extracting communities from graphs and matrices have been proposed. In this paper, the objective data is a bid data which represent a participation record of companies in bids. A community in bid data means a set of companies which often participated in multiple bids. We aim at applying the community extraction to finding bid rigging groups. In order to achieve the goal, we propose a biclustering method based on the density of bipartite graphs and the characteristic extraction by the nonnegative matrix factorization.

This article reconsiders how to judge judicial independence by using the Japanese judicature, one of the allegedly-most dependent judiciary branches. In their influential work, Ramseyer and Rasmusen (2003) argue that judges who once belonged to a leftist group take longer to reach a 'moderately prestigious status' under the long-term conservative rule of Japan. Their method does not, however, deal appropriately with the possibility of judges not reaching this position because the judge dies, retires early, or is still at the early stage of her career. Ramseyer and Rasmusen also mistakenly assume that all judges will eventually obtain this position. This article develops a survival analysis model of judicial careers and attempts to solve the problems of censoring, left truncation, and split population. We also offer a way to utilize a matching procedure to estimate average treatment effects on censored time-to-event as well as event occurrence. We re-analyze a corrected version of Ramseyer and Rasmusen's data using their and our methods. One of the most important findings is that, contrary to what Ramseyer and Rasmusen argue, leftist judges are not discriminated against in terms of the timing of promotion.

Scholars are interested in not just what event happens but also when the event happens. If there is dependence among events or dependence between time and events, however, the currently common methods (e.g., competing risks approaches) produce biased estimates. To deal with these problems, this article proposes a new method of copula-based ordered event history analysis (COEHA). A merit of working with copulas is that, whatever marginal distributions time and event variables follow (including the Cox model), researchers can derive whatever joint distribution exists between the two. Application of the COEHA model to a dataset from civil wars supports two controversial hypotheses. First, as wars become longer, rebel victory becomes more likely but settlement does not (there is dependence between time and events at both tails). Second, stronger rebels make wars shorter but do not necessarily tend to win, as experts predict but fail to establish (rebels' strength shortens time but has no effect on which events occur). Supplementary materials for this article are available online.

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Why so many legacy Diet members? This article estimates the effect of being legacy candidates on the "vote succession rate" (i.e. the ratio of citizens who vote for a candidate in an election to citizens who also will vote for the candidate's successor in the next election). This study proposes comparing legacy challenger with non-legacy challengers, not incumbents. This new statistical method estimates the effects of party and personal votes on the vote succession rate as well. We analyze the data of the Liberal Democratic Party candidates under the single member district system and find as follows: (i) the legacy challengers' advantage against non-legacy challengers is not less than the incumbents'; (ii) the effect of party votes is the same as that of legacy votes, but the effect of personal votes is not confirmed; and (iii) the legacy challengers' advantage emerges not because they are young or reelected many times.

Weak electoral registration requirements are commonly thought to encourage electoral participation, but may also promote electoral fraud. As one possibility, candidates and their supporters can more easily mobilize voters who do not reside within the district to register there fraudulently and vote for that district's candidates. We statistically detect this classic type of electoral fraud for the first time, by taking advantage of a natural experimental setting in Japanese municipal elections. We argue that whether or not a municipal election was held in April 2003 can be regarded as an "as-if" randomly assigned treatment. A differences-in-differences analysis of municipality-month panel data shows that the increase in the new population just prior to April 2003 is significantly larger in treatment municipalities (with an election) than in control ones (without an election). The estimated effects are decisive enough to change the electoral results when the election is competitive. We argue that our approach-"election timing as treatment"-can be applied to investigate not only this type of electoral fraud but also electoral connections in other countries.

In many applications of survival analysis, the risk of an event occurring for one reason is dependent on the risk of the same event occurring for another reason. For example, when politicians suspect they might lose an election, they may strategically choose to retire. In such situations, the often-used multinomial logit model suffers from bias and underestimates the degree of strategic retirement, for example, to what extent poor prior electoral performance diminishes electoral prospects. To address this problem, the present article proposes a systematically dependent competing-risks (SDCR) model of survival analysis. Unlike the frailty model, the SDCR model can also deal with more than two risks. Monte Carlo simulation demonstrates how much the SDCR model reduces bias. Reanalysis of data on U.S. congressional careers (Box-Steffensmeier and Jones 2004) documents the strategic retirement of representatives, indicating that electoral pressure is more effective at turning out incumbents than previously recognized.

This article defines the mechanical effect of electoral systems according to the literature on causal inference. An electoral system is decomposed into six parts: assembly size, district magnitude, malapportionment, geographical vote distribution, interaction between these, and electoral formula. The article proposes a new index of disproportionality, which is derived from the log likelihood ratio of the multinomial distribution. The mechanical effect of electoral systems on disproportionality is illustrated using simulation as well as election data from both Houses of Japanese Diet from 1890 to 2007.

Legislative scholars have debated what factors (e.g. divided government) account for the number of important laws a legislative body passes per year. This paper presents a monopoly model for explaining legislative production. It assumes that a legislature adjusts its law production so as to maximize its utility. The model predicts that socioeconomic and political changes increase the marginal benefit of law production, whereas low negotiation costs and ample legislative resources decrease the marginal cost of law production. The model is tested in two ways. The first approach compares the legislatures of 42 developed and developing countries. The second analyzes Japanese lawmaking from 1949 to 1990, using an appropriate method for event count time series data. Both empirical investigations support the model's predictions for legislative production.