法学研究 95 巻 7 号（2022：7）

Malapportionment and the Judiciary:＊

A Comparative Perspective

KASUYA, Yuko
Abstract
1. Introduction
2. Why Malapportionment Matters
3. The Importance of the Judiciary
4. Cross-national Analyses
5. Case Studies
6. Conclusion

Abstract
Malapportionment―the discrepancy between the share of legislative seats andthe share of the population within a given geographical unit―violates one of
the fundamental principles of democratic government, namely, one person, onevote. It also leads to undesirable governance results in many ways. Despite its
importance, however, we know little about the causes of malapportionment.
This paper examines this question with a focus on the role of the judiciary. I
hypothesize that countries with higher de facto judicial independence and higher
judicial activism tend to have lower levels of malapportionment. The basic logic
behind this idea is the following: in countries where the judiciary exercises
effective checks on violations of peopleʼs fundamental rights, the ruling elites are
more likely to amend the electoral laws to reduce malapportionment and/or to
avoid committing such violations in the first place. Cross-national statistical＊

This paper is a revised and updated version of the paper prepared for delivery at theAnnual Meeting of the American Political Science Association, Chicago, August 29―September 1, 2013.
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Malapportionment and the Judiciary

analyses, as well as case studies of the US and France, are provided. Bothapproaches provide evidence for these claims. Another noteworthy finding isthat when the degree of judicial independence is controlled for, the effects of
having a single-member district system lose their significance.

1. Introduction
Malapportionment―the discrepancy between the share of legislative seats andthe share of the population within a given geographical unit―is anathema to
one of the fundamental principles of democratic government, namely, one
person, one vote. At the same time, ample research has demonstrated that
unequal representation effects a number of undesirable consequences on
governance. It leads to, for example, overrepresentation of conservative interests,
regressive taxation, and biased transfers of state resources to overrepresented
areas. Despite the normative and practical importance of the issue,comparatively little research has analyzed the causes of malapportionment.
The present paper attempts to fill this gap. Specifically, it examines the roleof the judiciary in reducing malapportionment. I argue that de facto judicial
independence and activism are two factors associated with lower
malapportionment. When the judiciary can effectively provide checks against
this problem, the ruling elites are more likely to amend electoral laws to reduce
malapportionment and/or abstain from committing such violations in view ofcredible sanctions by the courts. A mixed-method strategy is employed to
examine these claims. I combine a cross-national statistical analysis with casestudies of France and the US. Both types of analyses offer findings consistent
with my argument.
This paper is related to several strands of research in comparative politics.
First, this paper contributes to the comparative study of electoral systems. As
Samuels and Snyder (2001: 652) have remarked in their important article on the
topic, the study of malapportionment has “curiously escaped” the attention ofscholars. Although recent interest has been growing regarding this topic, there
are still many holes to be filled in the literature. In particular, in contrast to
research on the consequences of malapportionment (reviewed later), we know
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法学研究 95 巻 7 号（2022：7）

little about why and how malapportionment is created and sustained in acomparative context. Second, this paper contributes to the expanding field of
judicial politics. During the past several decades, scholarship on courts has
expanded exponentially; this is particularly so among studies of emerging
democracies (Kapiszewski and Taylor 2008). This paper follows this trend. Third,
at a broader level concerning the quality of democracy, this paperʼs argument
stresses the importance of “horizontal accountability” (OʼDonnell 1998). By
examining one of the mechanisms of horizontal accountability, this paper aims
to contribute to the literature that offers suggestions on how to improve thequality of democracy.
I begin by surveying the degrees of malapportionment globally to showthat great variation exists. Section 2 reviews the existing literature describing theconsequences and causes of malapportionment. In Section 3, I outline myframework and hypotheses. Section 4 offers cross-national analyses. Case studiesof the US and France are supplied in Section 5.

2. Why Malapportionment Matters
Malapportionment Around the World
Malapportionment exists when there is a wide discrepancy between the share oflegislative seats and the share of the electorate in a given electoral district. If a
country uses an electoral formula with a single nationwide district, there is no
malapportionment; in this instance, the country may be said to have perfectly
apportioned districting. This type of electoral system is found only in a handful
1）of cases (e.g., Israel, Namibia, the Netherlands, and Sierra Leone) .

Thus,malapportionment is a common characteristic of most electoral systems.
Malapportionment can be measured by a formula called MAL, which isdetailed in Samuels and Snyder (2001) . It takes the absolute value of thedifference between each districtʼs seat and population (or the number of registered

1） Although Peru (1993) shows zero malapportionment in Figure 1, its electoral system(PR with nationwide constituency) has changed since 2000, and is thus not mentioned
here.
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2）

voters) shares, adds them, and then divides by two.

One advantage of thismeasure is that it yields comparable values across countries and electoral
formulae.
Using MAL, Figure 1 displays the degrees of malapportionment for the
lower legislative chambers in 79 countries in recent elections. For example, if acountry has a value of 10 percent, it means that 10 percent of available seats areallocated to districts that would not receive these seats if there were no
malapportionment.
The Consequences of Malapportionment
Malapportionment leads to undesirable consequences in a number of ways.
First, it creates “rural-conservative bias” in legislative representation (Snyder andSamuels 2004). Malapportionment usually leads to the overrepresentation ofrural interests because rural districts tend to elect larger numbers of legislatorswith a smaller share of the electorate. This tendency is reported in many
malapportioned systems, including in Latin America (Snyder and Samuels ibid),
Japan (Christensen and Johnson 1995), India (Bhavnani 2021), and the US Houseof Representatives prior to the apportionment revolution (Ansolabehere andSnyder 2008) . Malapportionment also sustains electoral authoritarianism(Higashijima and Kasuya 2022), as well as the legacies of authoritarianism in post-transition democracies. Analyzing Latin America, Bruhn, Gallego, andOnoratto (2010) show that overrepresented areas are more likely to vote forparties close to pre-democracy ruling groups. This happens because of thegerrymandered electoral districting authored by authoritarian elites at the timeof democratization.
Second, theorized as a consequence of rural-conservative biases,
malapportionment skews the collection and redistribution of government
resources. Ardanaz and Scartascini (2013) show that countries with higher

2） 0.5 Σ |s i –p i |, where s is the seat share and p is the population share of the ith districtagainst the national total. For other measures of malapportionment, see Samuels and Snyder (2001). For a more nuanced measure of malapportionment, see Kamahara et al.
(2021).
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法学研究 95 巻 7 号（2022：7）

Figure 1. Malapportionment in 79 countries
Sierra Leone（1996）
Peru（1993）
Netherlands（1996）
Namibia（1996）
Israel（1999）
Latvia（1995）
Italy（1996）
Malta（1996）
Finland（1991）
Sweden（1998）
Ukraine（1998）
Slovakia（1994）
Estonia（1995）
Cyprus（1995）
USA（1992）
New Zealand（1997）
Slovenia（1997）
Portugal（1995）
Poland（1997）
Switzerland（1995）
Costa Rica（1994）
Australia（1996）
Ireland（1992）
Czech Republic（1996）
Hungary（1998）
Benin（1995）
Burkina Faso（1997）
Uruguay（1992）
South Africa（1995）
Germany（1994）
Senegal（1998）
Barbados（1994）
Russia（1995）
Honduras（1997）
Paraguay（1993）
Greece（1997）
Romania（1996）
Thailand（1996）
UK（1997）
Japan（1995）

Sri Lanka(1994)
Mali(1997)
Denmark(1997)
Panama(1993)
Nicaragua(1996)
Guatemala(1990)
India(1991)
Mexico(1997)
Austria(1994)
Norway(1993)
Nepal (2008)
France(1998)
El Salvador(1997)
Venezuela(1998)
Liechtenstein(1997)
Belize(1993)
Jamaica(1997)
Canada(1997)
Dominican Rep.(1986)
Seychelles(1998)
Turkey(1995)
Georgia(1995)
Brazil(1998)
Spain(1996)
Korea(2000)
Andorra(1997)
Colombia(1994)
Gambia(1992)
Argentina(1995)
Chile(1997)
St. Lucia(1997)
Malawi(1994)
Bolivia(1997)
Iceland(1995)
Zambia(1996)
Ghana（1996）
Kenya（1997）
Ecuador（1998）
Tanzania（1995）
0

5 10 15 20 25 30%
MAL0

5 10 15 20 25 30%
MAL

Source: Compiled by the author based on Samuels and Snyder (2001), except for Nepal. The score for
Nepal is calculated by the author based on data from the Nepalese Election Commission.
Note: The election year used to calculate the value is in parentheses. The value for New Zealand isadjusted based on the authorʼs calculation. Koreaʼs score uses data from the 2000 election and thus
differs from Samuels and Snyder (ibid). It was calculated by Yuta Kamahara based on data from the
Korean Election Commission.
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Malapportionment and the Judiciary

malapportionment are associated with more regressive taxation because
overrepresented elites can block legislative attempts to introduce progressive tax
schemes. On the redistribution side, a malapportioned legislature tends totransfer state resources more heavily to overrepresented territories. This effecthas been found for the US (Ansolabehere and Snyder 2008), Latin America(Gibson, Calvo, and Falleti 2004), and Japan (Horiuchi and Saito 2003).

In short, malapportionment is neither just a matter of democratic ideals
nor a minor detail of electoral systems but can have significant consequences forvarious aspects of politics.
Existing Research
Despite the worldwide existence of malapportionment and its undesirable
consequences, its causes are still understudied. So far, cross-national empiricalanalyses have pointed to the following factors. The first is district magnitude. A
single-member district (SMD) plurality formula is associated with a higher
degree of malapportionment than a proportional representation system (Samuels
and Snyder 2001, Horiuchi 2004, Ardanaz and Scartascini 2013). Two reasons havebeen suggested for this phenomenon (Samuels and Snyder 2001: 663). The first is amechanical explanation. In SMD systems, there is but a single representative tobe elected from each district. By comparison, multi-member districts (MMD)
can elect variable numbers of representatives. In the latter, if geographic units
cannot be subsumed into other districts for historic or administrative reasons,the number of representatives elected from a given district can be adjusted,
whereas this kind of adjustment is impossible in SMD systems. The second
reason identified is political. In SMD systems, politicians as individuals havehigher stakes in reapportionment decisions since reapportionment would affectthe boundaries of the districts they represent with a greater likelihood than in
PR systems. Thus, legislators in SMD systems tend to resist reapportionment
reform more strongly than those in MMD systems, rendering such adjustments
3）

slower.

Second, economic inequality is associated with malapportionment(Horiuchi 2004, Ardanaz and Scartascini 2013) . There are two suggested

mechanisms according to which this relationship holds. First, inequality in
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法学研究 95 巻 7 号（2022：7）

assets and income at the time of democratic transition creates incentives among
outgoing elites to install districting plans favoring their support bases so that
their power can be retained in the post-transition period (Samuels and Snyder
2004, Ardanaz and Scartascini 2013). Second, Horiuchi (2004: 182) suggests thatonce malapportionment exists, politicians from rural, depopulated, and poor
areas are overrepresented and exercise their political power to preserve the status
quo.
Scholars have hypothesized about other factors, though they lack empiricalsupport. For example, Samuels and Snyder (2001) test whether it matters if acountry adopts a two-tier electoral system and/or federal system; they find it
does not. They also examine the population size and the level of democracy
within countries but find insignificant results. They do, however, find that Latin
America, compared to other regions in the world, had statistically significant
high malapportionment. However, this regional effect disappeared once theeffect of economic inequality was controlled for (Horiuchi 2004).
In a recent study, Ong et al. (2017) have shown that the degree of democracy
and malapportionment has a curvilinear relationship. At the very high levels of
democracy where the checks-and-balances institutions can contain politiciansʼ
incentives for malapportionment, while at the very low levels, or in regimes
where elections are de facto absent, elites do not have incentives tomalapportion. It is at the middle level of democracy, or in regimes with regularelections but weak accountability institutions, where levels of malapportionment
tend to be higher.
My theory employs a similar logic to Ong et al. (2017) but has a specificfocus on one of the accountability institutions within a political regime: thejudiciary. In the next section, I provide the details of my conjectures.

3） It is more appropriate to use electoral formulae, rather than the district magnitude, toexplain the circumstance. The case of Japan illustrates this point. When the lower houseused the single non-transferable electoral formula with MMD before the 1994 electoral reform, politicians had strong incentives to keep the status quo boundaries, and hence little
redistricting took place. The degree of malapportionment was about 17 percent in the1993 elections (based on authorʼs calculation).
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Malapportionment and the Judiciary

3. The Importance of the Judiciary
I a rg u e t h at t h e j u d i c i a r y p l ay s a n i m p o r t a n t ro l e i n i n f l u e n c i n gmalapportionment. My starting point is what many malapportionment scholars
have noted already: Malapportionment is fundamentally a product of politicalmanipulation by those in power (e.g., Snyder and Samuels 2001, Ardanaz and
Scartascini 2013) . The task, then, is to explore under what conditions suchmanipulation can occur. To put it differently, how can political manipulation becurtailed? I propose that there are at least three ways that the judiciary can makean impact. First, the presence of a judicial review system creates an opportunity
for citizens or affected parties to litigate against malapportionment. Judicial
review is the doctrine according to which legislative and executive actions are
subject to review by the judiciary. While the details of its institutional design
vary depending on the country (Ginsberg and Versteeg n.d.), an overwhelming
number of countries around the world have adopted some form of judicial
review. In one statistical assessment, as of early 2000, 85 percent of countries
had adopted such a system, with 71 percent of the remaining countries
4）

institutionalizing it as of 2011. Some might think that for judicial review to be
invoked, a constitutional provision on equal suffrage needs to exist. Most recent
constitutions satisfy this condition.

5）

As of 2013, of the 121 countries in theworld with populations greater than 1 million, 89 (73 percent) had constitutions
referring to equal representation, while 30 (25 percent) did not. The remaining
6）

two countries―Israel and the UK―have no written constitutions. Yet, even insuch cases, judicial review can be invoked based on existing electoral laws

4） The figure of 85 percent is reported in Romeu (2006: 103, 125), in which the author
states that out of 193 independent states, 164 have known some form of judicial review,
while 25 have not. Ginsberg and Versteeg (n.d.) reports that as of 2011, 71 percent of 204
countries, including those that have ceased to exist, have adopted the institution.
5） In my cross-national analyses provided later, all countries in the sample have some formof judicial review.
6） Based on the authorʼs calculation. The phrases coded “yes” include “equal protection by
the laws”; “equality under (the) law”; “equality under the constitution”; “equality in the value of a vote”; “one person, one vote.”
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法学研究 95 巻 7 号（2022：7）(Holland 1991). In sum, judicial review is a prerequisite for the courts to play arole in reducing malapportionment, and in the contemporary context, mostcountries already provide this institutional setting.
The second aspect of the judiciary allowing it to help reduce
malapportionment may be found in its independence from political pressure.
Here, the distinction between de jure and de facto judicial independence isimportant (Feld and Voigt 2003, Hayo and Voigt 2005, Linzer and Staton 2011, RiosFigueroa and Staton 2014) . De jure independence refers to the formal rules

designed to insulate judges from undue political and/or social pressure. The
major indicators of de jure independence include judgesʼ fixed tenure,multilateral appointment procedures, and judicial budgetary autonomy. De facto
independence embraces behavioral aspects. Two types of characteristics areassociated with this concept. First, judges must be able to form their opinions
independent of external pressures. Second, courts are considered de facto
independent when their decisions are enforced in practice, even when politicalactors would rather not comply.
I argue that the judiciaryʼs de facto, rather than de jure independence, canreduce malapportionment. For example, Feld and Voigt (2003) show that whilede jure judicial independence does not have any significant impact on economic
growth, de facto judicial independence positively influences GDP growth. Their
explanation behind this result is that peopleʼs behavior depends more on theirevaluation of the de facto independence rather than de jure independence of the
judiciary. I employ the same logic. As mentioned, malapportionment is often the
result of political manipulation in districting decisions. If some actors―an
opposition party or a group of citizens―were desirous of changing the statusquo, they would turn to the judiciary if deemed reasonably independent inpractice. If the courts were known to be corruptible by political elites, these
actors would not seek judicial relief to begin with. Even if they did, judges
under the influence of the elites would be more likely to uphold the status quo.
In addition, it is possible that the expectation of judicial review by anindependent court could exert pressure on incumbent politicians who control
districting to refrain from outright manipulation.
Third, judicial activism can reduce malapportionment. Although judicial(9)114

Malapportionment and the Judiciary

Figure 2. The Sequential Framework(1) Judiciary can review the acts and decisions of the legislature and the executive (background)(2) Judiciaryʼs de facto indepaendence is expected to leadto litigation and verdict against malapportionmant (H1)

(3) Judicial activism is expected
to lead to verdict against
malapportionment (H2)Malapportionment

Complaints

Litigation

Verdict

Implementation ofverdict

Reducedmalapportionment

activism is a “loaded term” (Lindquist and Cross 2009: 1), one commonly useddefinition describes it as the acts of the judiciary that invalidate the decisions
and acts of the legislative and executive branches, in contrast to when judicial
actors merely confine themselves to the adjudication of legal conflicts. Judicial
independence may be a prerequisite for judicial activism, but judicial
independence does not always correlate with robust activism. For example,
Germany and Japan both have relatively independent judiciaries. Yet theGerman judiciary is known to be highly active, while its Japanese counterpart ischaracterized by its passivity. A lack of judicial activism contributes to themaintenance of the status quo, including a high degree of malapportionment.
Complaints may be made, but if judges have strong reservations about
intervening in politics, the status quo tends to persist.
Figure 2 depicts the ways in which these three factors can lead to reducing
malapportionment. Among them, the judiciaryʼs de facto independence andactivism will be examined with cross-national data. The effect of judicial review
is difficult to test since it is present in most countries. Thus, my framework
positions judicial review as a background factor, and empirical examination will
be conducted only for de facto independence and activism.
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法学研究 95 巻 7 号（2022：7）

Based on the above discussion, I test the following two hypotheses.
Hypothesis 1: Malapportionment tends to be lower in countries where de facto
judicial independence is higher, other things being equal.
Hypothesis 2: Malapportionment tends to be lower in countries where judicial
activism is higher, other things being equal.
By no means am I the first to highlight the role of the judiciary in studies
of malapportionment. It is well known and thoroughly researched that Supreme
Court decisions led to a “reapportionment revolution” in the US in the 1960s(e.g., Ansolobehere and Snyder 2008, Cox and Katz 2002). This paper is an extensionof studies of the American experience to the cross-national context. Also, in
analyzing Latin America, the investigation of Snyder and Samuels (2004) points
out the role of judicial oversight but does so in a dismissive manner. The
authors posit that judicial oversight would not be a remedy because most courts
in Latin America are “notorious both for their politicization and for their
weakness” (Snyder and Samuels ibid: 156 ―157). Their evaluation may appear
counter to this paperʼs claims, but in fact, it is not. What the Latin Americancases imply is that by making the courts less politicized and stronger ―equivalent to making them de facto independent and activist―there is a good
possibility that malapportionment can be reduced.

4. Cross-national Analyses
Judicial Independence
In this subsection, I test my first hypothesis with cross-national data using an
ordinary least squares (OLS) regression. My dependent variable is the degree ofmalapportionment (MAL) across countries in recent elections. The logged values
are used because of the highly skewed distribution. The data comes from thesame sources as in Figure 1. This data is the most extensive cross-national dataon malapportionment currently available, but one limitation is that it measures(11)112

Malapportionment and the Judiciary

the degree of MAL only for a single election. Nevertheless, since the degrees of
MAL do not vary so widely from one election to the next, the use of this data
can be justified.
The independent variable of interest is de facto independence of the
judiciary, denoted Judiciary. I use de facto judicial independence scores compiled
by Linzer and Staton (2011). This score measures the concept of de facto judicial
independence as a latent variable drawing upon a number of existing indexes. It
ranges from zero to one, with one being the most independent. The original data
covers around 200 countries for 50 years. I use the natural log of this score foreach country at the time of the election for which MAL is calculated. Judiciaryis expected to be associated with lower MAL.
In order to control for the effects of other influencing factors, I include thefollowing control variables.

7）

One is a dummy variable pertaining to whether acountry has adopted a single-member district system, named SMD (Samuels andSnyder 2001, Ardanaz and Scartacini 2013). It is expected that countries adopting

SMD systems have higher malapportionment than those with non-SMD
systems. Data is obtained from Samuels and Snyder (2001). The other control
variable relates to the degree of economic inequality, called inequality. Several
studies (Horiuchi 2004; Ardanaz and Scartascini 2013) have shown that higher
inequality is associated with higher malapportionment. This variable was thenatural log of the Gini coefficient during the 1990s. The data comes from theUnited National University, World Institute for Development Economics
8）

Research. Inequality is expected to have a positive effect on MAL.
As a first-cut examination of Hypothesis 1, Figure 3 presents the plot of
malapportionment and de facto judicial independence. The figure shows anegative relationship between the two, offering preliminary rough support for
Hypothesis 1.

7） I do not include other variables that previous studies have included, but have found tohave insignificant effects. These include the size of a country, a dummy variable for federalism, the level of democracy, a dummy variable for tiered electoral systems, and dummy
variables for the worldʼs major regions and change in urban population ratio.
8） Retrieved from: http://www.wider.unu.edu/research/Database/en_GB/wiid/.
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法学研究 95 巻 7 号（2022：7）

0.00

0.05

0.10

mal
0.15

0.20

0.25

Figure 3. Malapportionment and judicial independence in 72 countries

0.2

0.4
0.6
0.8
de facto judical independence

1.0

Source: Compiled by the author.

Table 1 presents the regression estimates. Models 1, 2, and 3 are the resultsof bivariate regression testing the effects of judicial independence, districtmagnitude, and inequality. All of them have statistically significant relationships
in the expected direction. Model 4 is a simplified version of previous studies(Samuels and Snyder 2001, Horiuchi 2004, Ardanaz and Scartascini 2013) . The

results, in principle, echo the previous findings.
Model 5 is the full model, including the variables pertaining to judicial
independence, SMD, and inequality. It shows that judicial independence has asignificant and negative effect on the malapportionment index after controlling
for the effects of electoral formulae and inequality. The estimated coefficient
suggests that a 1 percent increase in judicial independence yields a 0.48 percent
decrease in the malapportionment index. This effect is statistically significant at
the 5 percent level. Inequality also remains significant after controlling for theeffects of judicial independence and electoral formulae. With a 1 percent change
in the Gini index, a 0.97 percent increase in the malapportionment index is(13)110

Malapportionment and the Judiciary

associated with statistical significance at the 1 percent level.
It is worth noting that when judicial independence is included, the effect of
SMD is no longer statistically significant. This happens regardless of thepresence or absence of Inequality (see Models 5 and 6). This suggests that thepresence of an independent judiciary mitigates the technical difficulties ofdrawing boundaries and/or stronger political incentives to block redistricting
associated with the SMD system. As illustrated in the next section, this is what
happened in the case of the US House of Representatives.
A problem of multicollinearity is detected if one compares the results ofModels 1 and 5. In Model 1, the coefficient of Judiciary is －0.827, and that inModel 5 is －0.488. This downward change is mostly the result of including
Inequality in Model 5.

9）This, in turn, suggests the presence of a significant

correlation between Judiciary and Inequality. Indeed, the correlation coefficient
10）

between the two is －0.47, statistically significant at the 1 percent level.

Thismeans that higher judicial independence is associated with lower economic
inequality. There are two possible interpretations of this relationship. First,
judicial independence reduces inequality through providing checks on politicaldecisions that favor the rich. Another interpretation is that a more egalitariansociety allows for the emergence of an independent judiciary because no single
group dominates politics. When there is a dominantly powerful group, thatgroup is likely to subsume the judiciary under their control. Future researchshould investigate which way the direction of influence runs. At this stage, what
can be said about the results is that the current value of the coefficient of
Independence has to be taken with some caution, owing to the potential bias
11）

resulting from a multicollinearity problem.

Overall, the results of OLS are consistent with Hypothesis 1.

9） This is because when Judiciary and SMD are included in the model, as in Model 6, thecoefficient value for Judiciary remains virtually the same as in Model 1.
10） The correlation coefficient between Independence and SMD is －0.23, and that between
Inequality and SMD is 0.053; neither is statistically significant.
11） One solution to have a more accurate estimate is to increase the number of observations (especially increasing the number of MAL) in the future.
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法学研究 95 巻 7 号（2022：7）

Table 1. Determinants of the Malapportionment of Seats in Lower Chambers(1)
Judiciary

(2)

(3)

(4)

－0.827＊＊＊(0.217)
＊＊

SMD

(6)
－0.742＊＊＊(0.235)(0.226)

＊＊

0.469

0.414

0.297

0.270

(0.213)(0.199)(0.202)(0.209)1.316＊＊＊

1.240＊＊＊

0.976＊＊＊(0.311)(0.306)(0.324)Inequality
Intercept(5)－0.488＊＊－3.464＊＊＊ －3.229＊＊＊ －7.833＊＊＊ －7.700＊＊＊ －6.948＊＊＊ －3.516＊＊＊(0.141)(0.125)(1.125)(1.100)(1.134)(0.146)

Adj. R-sqʼed

0.158

0.051

0.197

0.235

0.271

0.166

N. of Obs.

72

72

69

69

69

72

Note: Robust standard errors in parentheses; p ＜ 0.1, p ＜ 0.05, p
*

**

***

＜ 0.01

Judicial Activism
Unlike the data on judicial independence, cross-national data measuring thedegree of judicial activism is underdeveloped. The most extensive thus far isfound in Cooter and Ginsberg (2003), covering 14 countries. Their definition of“judicial daring”―which they interchangeably call “judicial activism”―includes
the following: (1) willingness to make new law through interpretation, or (2)willingness to adopt interpretations contrary to government preferences (ibid:
16). This is a five-point scale score based on evaluations by 23 experts (seeAppendix for actual values). One of the limitations of this measurement is its

ambiguity with regard to the time frame; Cooter and Ginsberg do not specify
the time period for evaluation. Given that their paper was published in the early
2000s, I use this index with the assumption that experts rated the degree of
judicial activism around the late 1990s or early 2000s. This matches the time
period for which MAL scores have been calculated.
Figure 4 plots the judicial activism scores and MAL for 12 countries where
both measurements are available. It shows that the lower degrees ofmalapportionment are associated with higher degrees of judicial activism. This
result should be viewed with caution since other possibly important factors are
not controlled for. In addition, there is no statistically significant relationship in(15)108

Malapportionment and the Judiciary

0.00

0.02

mal
0.04
0.06

0.08

0.10

Figure 4. Judicial activism and malapportionment

2.0

2.5

3.0
3.5
Judicial activism

4.0

4.5

Source: Compiled by the author.

the bivariate regression. Nevertheless, it at least suggests some degree ofplausibility for Hypothesis 2. In the next section, I provide case studies of the
U S a n d Fr a n c e t o i l l u s t r at e h ow j u d i c i a l a c t iv i s m c a n i n f l u e n c emalapportionment.

5. Case Studies
The United States
The US typifies high judicial independence (0.97) and high judicial activism(4.5). It likewise provides a clear-cut example of how a nationʼs judiciary has
12）brought about reduced malapportionment.

In March 1962, the Supreme Court handed down its decision in the case ofBaker v. Carr, in which urban plaintiffs in Tennessee had challenged the state12） This section draws heavily on Cox and Katz (2002).
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法学研究 95 巻 7 号（2022：7）

legislatureʼs failure to reapportion despite widespread population shifts towards
urban districts. The Warren Court ruled that Bakerʼs case was justifiable in lightof the Fourteenth Amendmentʼs guarantee of equal protection of the laws to all
citizens. Similar lawsuits followed immediately after the verdict. In 1964,
through Reynolds v. Sims, the Court formulated the “one person, one vote”
standard that has since become a democratic motto around the world. In 1973,
it reaffirmed the requirement that districts be apportioned “as mathematicallyequal as reasonably possible.” Further, in 1983, the Supreme Courtʼs decision set
a numerical standard that congressional districting should be done with adeviation of 0.7 percent from the target figure or else be deemedunconstitutional.
The Supreme Courtʼs decisions changed the rules of apportionment so thatthe state-level courts now play an important role. Since 1929, seats have been
automatically apportioned among the states according to population after eachdecennial census. However, it has been up to the state to define the boundaries
of its allotted number of districts―generally by state legislation involving bothlegislatures and governors. If a law did not pass, then the next election was held
under the old law, which kept malapportionment intact. After the
reapportionment revolution ushered in by the Supreme Court, when the statelegislature could not pass new laws, the highest state court imposed a plan.
Thus, state legislatures had to plan districting under the threat of the courtsʼ
involvement.
Figure 5 displays the degree of malapportionment in the US House ofRepresentatives elections from the end of WWII until the 1990s. The blue line
indicates the degree of national-level malapportionment. The red line picturesinterstate malapportionment, which is the extent to which each state receives an
unfair share of seats according to its state-wide population. The box plot shows
the distribution of malapportionment among the 50 states, with the middle linein the box indicating the median value. Figure 5 reveals that the sources ofm a l ap p o r t i o n m e n t d u r i n g t h e p re - re fo r m e ra m o s t ly c a m e f ro m
malapportionment within each state. In other words, the distribution of seats toeach state has been relatively fair throughout the post-WWII period. The
narrowing gap between the red and blue lines from the late 1960s to the mid(17)106

Malapportionment and the Judiciary

Figure 5. Malapportionment in the US House of Representatives since WW II
0.25

0.20

0.15

0.10
0.05

97―98

95―96

93―94

91―92

89―90

87―88

85―86

83―84

81―82

79―80

77―78

75―76

73―74

71―72

69―70

67―68

65―66

63―64

61―62

59―60

57―58

55―56

53―54

51―52

49―50

45―46

47―48

0.00

Source: Compiled by the author, based on data provided on Scott Adlerʼs home page.13）

1970s indicates the movement of states away from biased districting practices
around this period. The figure, as a whole, confirms the standard story that theSupreme Courtʼs decisions in the 1960s have dramatically reduced
malapportionment in the elections of the US House of Representatives.
FranceAlthough the case of France is not as clear-cut as that of the US, it is anothercountry in which the judiciary has played an important role in reducing
malapportionment. France scores relatively high in both de facto judicial
independence (0.74) and activism (3.42). It also uses an SMD system with two
14）rounds of voting.

The French Constitution stipulates that each department

must have at least two representatives in the National Assembly. The Ministry ofInterior plans the boundaries, and the government promulgates the districting13） http://sobek.colorado.edu/~esadler/Congressional_District_Data.html
14） This system has been used consistently under the Fifth Republic that began in 1958,
except for the PR system-based 1986 election. This change was initiated and implemented
by the Socialist government, but after their defeat in the 1986 election, the SMD system
was quickly re-adopted.
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法学研究 95 巻 7 号（2022：7）

plan as a decree.
In France, the Constitutional Council is established to conduct judicial
review. It began addressing the malapportionment issue beginning in the 1980s.
In the aftermath of the 1986 election, a group of socialist deputies led by Pierre
Joxe appealed to the Constitutional Council that the existing districting planviolated the principle of equal suffrage. The plan in use at that time was a
product of the Gaullist government, prepared by then-Minister of the InteriorCharles Pasqua, and had been decreed just before the 1986 election. In theelection law of 1986 governing that yearʼs election, it was stipulated that no
districts could have a population differing from the national average district
population by more than 20 percent. Under Pasquaʼs plan, only 24 out of 96
departments met this standard (Balinski 2008: 183―184). Ruling against the Joxecase, the Council did not declare Pasquaʼs districting unconstitutional. However,
it issued a strong warning that deviation from the 20 percent standard should be
15）“reserved for exceptional cases.”
The Councilʼs warning in 1986 has served as a reference point for the
successive decisions and observations that the Council has delivered on
malapportionment subsequently. For example, in 2005, the Constitutional
Council issued an observation stating that the current Pasqua districting plan
was unsatisfactory and that reform should be undertaken, if not before the16）

coming 2007 election, then after.

The Pasqua districting plan of 1986, which

was based on the 1982 census, had been in use without alterations for elections
held in 1988, 1993, 1997, and 2002. As the government again failed to re-district
for the 2007 election, the Council issued another observation dated May 29,
2008.

17）

Citing the “regret” expressed in the abovementioned 2005 observation,

the Council stated that it was now “imperative” to reform the districting plan.
Shortly after the observation was made public, President Sarkozy tasked15） http://www.conseil-constitutionnel.fr/conseil-constitutionnel/francais/les-decisions/acces-par-date/decisions-depuis-1959/1986/86-208-dc/decision-n-86-208-dc-du-02juillet-1986.8273.html.
16） http://www.conseil-constitutionnel.fr/conseil-constitutionnel/francais/les-decisions/acces-par-date/decisions-depuis-1959/2005/2005-22-elec/decision-n-2005-22-elec-du-07juillet-2005.107207.html(19)104

Malapportionment and the Judiciary

Figure 6. Malapportionment in the French National Assembly since the 1980s
0.25

0.20

0.15

0.10

0.05

2012

2007

2002

1997

1993

1988

0.00

Source: Compiled by the author.

Alain Marleix, the then Secretary of State for Interior and Local Authorities, tomake a new districting plan, which was completed in 2010.

18）

Marleixʼs plan wasused in drawing district boundaries in the 2012 election.
Figure 6 displays the change in the degree of malapportionment in France
from the 1980s to the 2012 election. The structure of the graph is notably similar
to that of Figure 5. The increasing malapportionment from 1986 to 2007 can be
attributed to changing demographics, such as inter-regional migration, because
little else had changed. In the 2012 election, with the use of a new districting
plan, MAL declined to approximately 1986 levels. Although the 2010 districting
plan is far from perfect, this sequence of events illustrates that the judiciaryʼs
repeated warning against MAL stimulated the government to embark on
districting reform.

17） http://www.conseil-constitutionnel.fr/conseil-constitutionnel/francais/les-decisions/acces-par-date/decisions-depuis-1959/2008/2008-24-elec/decision-n-2008-24-elec-du-29mai-2008.108157.html
18） http://www.lefigaro.fr/politique/2008/07/12/01002-20080712ARTFIG00038-decoupageelectoral-marleix-tente-de-deminer-le-terrain-.php103(20)

法学研究 95 巻 7 号（2022：7）

6. Conclusion
This paper has argued that high levels of de facto independence and activism of
the judiciary can serve as one channel by which malapportionment can be
reduced. Although preliminary, both a cross-national statistical examinationand case studies have provided support for this argument. Another noteworthy
finding is that when the effect of judicial independence is included in the
regression model, the SMD electoral system is no longer a statisticallysignificant factor. This finding should be contrasted with those of previous
studies that consistently found SMD to be associated with higher
malapportionment. My result indicates that when the court can exercise effective
oversight, the effects of SMD ―either technical difficulties in districting or
politiciansʼ stronger incentives to resist reform, or both―are curtailed.
These results suggest that one solution to the problem of malapportionmentis to improve the independence and activist character of the courts. Snyder andSamuels (2004) have suggested that changing electoral formulae from SMD to
PR would be a possible remedy. The findings of this paper imply that suchchanges may not be necessary if the courts can exercise effective checks on
malapportionment.
There are, however, a number of issues to be addressed in a future versionof this research. First, to examine in detail how judicial independence affects
malapportionment, we need longitudinal data about malapportionment for alarge number of countries. Such data would also be useful in disentangling thecorrelation between inequality and judicial independence. Second, the numberof case studies may be helpfully increased. Currently, the paper only examines
cases scoring high values for both independent and dependent variables. In the
future, cases with lower values for both should be studied to glean a morecomprehensive understanding of the role of the judiciary.
More broadly, scholars should seek other causes of malapportionment toaccumulate more knowledge about this understudied topic. One factor worth
investigating is rules concerning redistricting. It can be expected that when apolitically insulated body is in charge of redistricting, as in the case of Mexicoʼs
19）

Federal Electoral Institute (IFE) since the late 1990s,

lower malapportionment(21)102

Malapportionment and the Judiciaryis the likely result. Conversely, when the incumbent government has the ultimate
decision-making power, malapportionment might be higher. The otherp o s s i b i l i t y i m p o r t a n t f a c t o r t u r n s o n c o n s t i t u t i o n a l ly j u s t i f i e dmalapportionment at the level of the lower legislative chamber. It is well-known
that many federal countries have a constitutional provision that deliberately
overrepresents smaller geographic unites at the upper chambers. Some countries
have similar constitutional mandates for their lower chambers. Franceʼs
National Assembly is one such example, as mentioned in my case study.

20）

Malapportionment resulting from constitutional quota is justifiable as legitimate
and thus should be separated from politically maneuvered malapportionment.
With the growing availability of cross-national and cross-sectional data on
malapportionment, these issues demand attention in the future.

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Appendix. Judicial Activism Score
Country

Activism score

US

4.5

Israel4.25

Netherlands

4

Belgium

3.5

France

3.42

Italy

3.3

Germany

3.25

Sweden2.5

Australia

2.38

Canada

2.3

Japan

2.14

Spain

2.14

NZ

2.11

UK

2.09

Source: Cooter and Ginsberg 2003.

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