e propose a comprehensive statistical model for analyzing multiparty, district-level elections. This model, which provides a tool for comparative politics research analogous to that which regression analysis provides in the American two-party context, can be used to explain or predict how geographic distributions of electoral results depend upon economic conditions, neighborhood ethnic compositions, campaign spending, and other features of the election campaign or aggregate areas. We also provide new graphical representations for data exploration, model evaluation, and substantive interpretation. We illustrate the use of this model by attempting to resolve a controversy over the size of and trend in the electoral advantage of incumbency in Britain. Contraiy to previous analyses, all based on measures now known to be biased, we demonstrate that the advantage is small but meaningfkl, varies substantially across the parties, and is not growing. Finally, we show how to estimate the party from which each party's advantage is predominantly drawn. w e propose the first internally consistent statistical model for analyzing multiparty, districtlevel aggregate election data. Our model can

The regression-discontinuity (RD) design has experienced a resurgence of interest in many fields, including political science. Following David Lee’s pioneering work on the incumbency advantage in U.S. House elections, many scholars have begun to apply RD designs to popular elections. Under certain assumptions, the RD design yields causal estimates that approach the gold standard of randomized experiments. There are good reasons to believe, however, that outcomes of narrowly decided U.S. Congressional elections are anything but random. Consistent with this notion, we demonstrate that bare winners and bare losers in U.S. House elections exhibit dramatic differences on key pretreatment covariates. Bare winners have substantially more financial resources than candidates who just lose and are far more likely to belong to the party that won the previous election in the district. Congressional Quarterly’s pre-election race ratings predict the outcomes of even extremely close elections with a high degree of accuracy. Close House elections are so predictable that it is impossible to achieve covariate balance between matched treated and control observations. We show that post-election recounts do not change election results often enough to account for the large imbalances in pre-election covariates that we observe. We conclude that bare winners and bare losers in U.S. House elections are not exchangeable ex ante. Therefore, the RD design is not valid in the case of U.S. House elections,

Competition in U.S. House elections has been declining for more than 50 years and, based on both incumbent reelection rates and the percentage of close races, the 2002 and 2004 House elections were the least competitive of the postwar era. This article tests three hypotheses that attempt to explain declining competition in House elections: the redistricting hypothesis, the partisan polarization hypothesis, and the incumbency hypothesis. We find strong support for both the partisan polarization hypothesis and the incumbency hypothesis but no support for the redistricting hypothesis. Since the 1970s there has been a substantial increase in the number of House districts that are safe for one party and a substantial decrease in the number of marginal districts. However, this shift has not been caused by redistricting but by demographic change and ideological realignment within the electorate. Moreover, even in the remaining marginal districts most challengers lack the financial resources needed to wage competitive campaigns. The increasing correlation among district partisanship, incumbency, and campaign spending means that the effects of these three variables tend to reinforce each other to a greater extent than in the past. The result is a pattern of reinforcing advantages that leads to extraordinarily uncompetitive elections. The 2004 House elections may have been the least competitive in American history. They were certainly the least competitive of the

discussions.

Since 1914, incumbent U.S. senators running for reelection have won almost 80 % of the time. We investigate why incumbents win so often, and how changes in electoral design would affect the value of senatorial seat. We allow for three potential explanations for the incumbency advantage: selection, tenure, and challenger quality, which are separately identified using histories of election outcomes following an open seat election. We specify a dynamic model of voter behavior that allows for these three effects, and structurally estimate the parameters of the model using U.S. Senate data. We find that tenure effects

on basic assumptions about individual preferences that are both empirically questionable and “not logically consistent with the basic assumptions on individual preferences made in economics.”(Milyo: 274) Two assumptions stand out in particular, that individuals have single-peaked, strictly quasiconcave preferences and that these are independent of other exogenous parameters. We argue in this paper that if voters do not have such wellbehaved preferences, inter-group bargains will be much harder to strike. Not only may optima be very difficult to locate but such equilibria are also more likely to be unstable. We then offer a new method to assess whether these assumptions hold empirically and apply it to the Israeli electorate. We find that in 1992 and 1996 the Israeli electorate clearly did not have Euclidean preferences and the evidence also strongly suggests that issues were not separable. The problem of peace in the Middle East has held a prominent place on the desk of American presidents for at least the last 25 years. After the Oslo Accords and especially in the last year of the Clinton Administration many were starting to become cautiously optimistic that an agreement between the Palestinians and the Israelis finally

We investigate why incumbents win disproportionately often. To do so, we structurally estimate the parameters of a dynamic model of voter behavior using U.S. Senate data. Our model specifies three potential reasons for the incumbency advantage: selection, tenure and challenger quality. Each of these separate e#ects is identified from data on histories of election outcomes. We estimate the parameters of the model using the method of maximum likelihood. We find that tenure e#ects are negative or small. The incumbency advantage is due to the average quality of incumbents being higher and to incumbents facing weaker challengers than candidates running for open seats.

Although natural experiments are increasingly prominent in the social sciences, they often have more in common with traditional observational studies than with randomized experiments. We illustrate our argument by examining the use of redistricting to estimate the personal vote. Strikingly, even if voters were redistricted randomly, previous uses of redistricting would not identify the causal effect of interest. We also find that the redistricting process is sufficiently nonrandom as to require significant covariate adjustment to overcome confounding. To avoid these difficulties, we propose a new design for estimating the personal vote and the partisan incumbency advantage that relies on the implementation of multiple redistricting plans. Analyzing data from U.S. House

The U.S. government is founded on and derives its legitimacy from the principle of the consent of the governed. Citizens can be satisfied with many forms of government, and the course of American political development might have been radically different if King George III had been responsive to the grievances of the colonies. However, history has demonstrated the longterm dangers of a government based on a short-term benevolent authoritarian regime; inevitably a despot rises to power. To protect against future despotism, the Founding Fathers renewed the ancient Roman method of expressing the consent of the governed: a representative government selected in periodic elections. Prominent political theorists define representative democracy in terms of meaningful choices presented to voters: Joseph Schumpeter defines representative democracy as “that institutional arrangement for arriving at political decisions in which individuals acquire the power to decide by means of a competitive struggle for the people’s vote. ” 1 Robert Dahl calls it “a system of control by competition. ” 2 Adam Przeworski discusses the institution as it

We study whether the incumbent status of previously elected parties and politicians translates into an electoral or incumbency advantage in the U.S. Senate, using a regression discontinuity (RD) design that compares states where the Democratic Party barely won a Senate election to states where the Democratic party barely lost. Since the Senate has only one hundred seats up for election every six years, the number of close races is small and standard RD estimation techniques are ill-suited for our problem. We develop a randomization inference framework that is appropriate for our small sample size, and show that the results obtained with our approach can be markedly different from results based on standard methods. Our framework is general and applicable to any RD design where small sample sizes constrain researchers ’ ability to make inferences, and is motivated by a recent strand of the literature that advocates interpreting RD designs as local randomized experiments. Our approach has two steps. The first is to select a window around the cutoff where a randomization-type condition is assumed to hold. Researchers can choose this window based on substantive knowledge