2024/30 “The Power of a Vote in Malaysia: Malapportionment Under UNDI18, AVR, and MA63” by Kai Ostwald

A university student talks with her mobile in front of the United Malays National Organisation (UMNO) banner at a campaign rally on the eve of the 15th general elections in Bera, Malaysia’s Pahang state on 18 November 2022. (Photo by Mohd RASFAN / AFP).


  • While often overlooked, electoral boundaries can strongly shape political competition and policy priorities. In Malaysia, the long-dominant United Malays National Organisation (UMNO) manipulated boundaries in ways that amplified the power of votes in its stronghold areas. This created significant discrepancies in the number of voters across electoral districts—known as malapportionment—and is strongly associated with distortions to governance and disillusionment with the political process.
  • The 2019 UNDI18 constitutional amendment lowered the voting age to 18 and introduced automatic voter registration. This increased the size of the electorate by a remarkable 40% between the 2018 and 2022 general elections. More recently, Anwar Ibrahim’s unity government has pledged to increase the parliamentary seat share of East Malaysia’s Sabah and Sarawak from the current 25% to 35%, despite the states already being significantly over-represented. Both these developments worsen the malapportionment in the country, potentially causing further political distortions.
  • Against the backdrop of already high levels of malapportionment, the impact of UNDI18 on malapportionment is more modest than most narratives suggest, though it is responsible for creating a number of problematic mega-districts. By contrast, implementing the proposed seat increase for Sabah and Sarawak would substantially worsen state and district level malapportionment. While this may be justified, given East Malaysia’s unique position in the federation—as well as a newfound political agency—there is little obvious justification for the ongoing discrepancies within Peninsular Malaysia, particularly the under-representation of Selangor.
  • A dominant narrative in Malaysia, voiced by numerous political elites in recent months, holds that reducing malapportionment is disadvantageous for ethnic Malays. This however reflects assumptions that are no longer valid following demographic developments and changes to Malaysia’s party system since 2013. To the contrary, in terms of electorate size, there are substantial similarities in the seats won by the Malay-majority Parti Islam se Malaysia (PAS) and their arch-rival Chinese-majority Democratic Action Party, while on average the largest seats were won by the Malay-majority Parti Keadilan Rakyat (PKR) and Amanah.
  • In short, there is no empirical basis for the ethnic-focused narrative. Recognizing this would facilitate constructive discussions around addressing malapportionment, particularly in light of the significant political reordering that a seat increase for East Malaysia would produce.

* Kai Ostwald is Associate Senior Fellow with the Malaysian Studies Programme at ISEAS – Yusof Ishak Institute. He is also Director of the Institute of Asian Research at the University of British Columbia, and Associate Professor in UBC’s School of Public Policy and Global Affairs.

ISEAS Perspective 2024/30, 25 April 2024

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The size and shape of electoral districts can profoundly impact political outcomes. Malaysia is a case in point: the strategic manipulation of district boundaries over decades played a key role in sustaining the electoral dominance of the United Malays National Organisation (UMNO) and its Barisan Nasional (BN) coalition partners prior to their 2018 defeat. This was achieved primarily through malapportionment—the unequal distribution of voters across electoral districts—which amplified the influence of voters in the BN’s stronghold areas, allowing the coalition to consistently secure parliamentary majorities well above their level of popular support.[1] 

While Malaysian politics have evolved dramatically since 2018, manipulated electoral districts continue to shape political representation and competition. Three key questions stand out. First, the UNDI18 constitutional amendment (in 2019) significantly increased the size of the electorate and appears to have exacerbated malapportionment, although to what extent and effect is yet unclear. Second, the BN’s defeat in 2018 decoupled East Malaysia’s party system from the Peninsula’s and catalyzed demands for greater East Malaysian influence in federal politics, including via an increase in parliamentary seats from the current 25% to 35% — which the manifesto of Prime Minister Anwar Ibrahim’s coalition pledged to do. If implemented, this move would further increase malapportionment, but it is likewise unclear to what extent. Finally, given the broader fragmentation of the party system, it is uncertain whether previous patterns of who benefits and who is disadvantaged from malapportionment still hold.  

This Perspective addresses those questions and reaches several conclusions. Malapportionment, which entails myriad costly distortions to politics and governance, remains high and would increase significantly through the introduction of new East Malaysian seats. While the unique position of East Malaysia may justify that, the extensive malapportionment in Peninsular Malaysia is less defensible. Importantly, constituency-level demographic changes and new coalition compositions mean dominant narratives around who benefits from malapportionment are now outdated and flawed. Updating the underlying assumptions provides an opportunity to address the most problematic boundary distortions.


Malapportionment arises when there are disparities in the number of voters across electoral districts. The figure below illustrates the effect through two hypothetical districts: District A has one voter, while District B has eight voters. Since each district has one seat in parliament, District A’s voter has significantly more power to shape parliamentary outcomes than does a voter in District B. In short, malapportionment amplifies the influence of voters in districts with relatively few voters, while diluting the influence of voters in districts with relatively many voters. As a result, the preferences of District A’s voter are overrepresented, which contradicts the normatively important “one person, one vote” principle. By creating incentives for political leaders to focus resources and policy decisions on over-represented voters, this dynamic creates extensive political distortions and fosters clientelistic behaviours.[2] On the side of voters, perpetual under-representation is associated with political disengagement.

Malapportionment illustrated

During its decades in power, UMNO systematically reshaped Malaysia’s electoral process in ways that provided it and its coalition partners fundamental advantages (Lim 2002, Ostwald 2017). This included reducing the size of electoral districts in areas where the coalition enjoyed strong support, allowing it to inflate its parliamentary seat share relative to its vote share. The effect of this cannot be overstated: in the 2013 general election, for example, malapportionment allowed the BN to secure a 20% parliamentary seat advantage despite losing the popular vote by 4%. By 2018, decades of manipulating electoral boundaries left Malaysia with unusually high levels of malapportionment by global standards (Ong, Kasuya, and Mori 2017).[3]

The Pakatan Harapan (PH) government that took power in 2018 pledged extensive reforms, including of the electoral process (Ting and Horowitz 2023). Among its successes was the UNDI18 constitutional amendment that lowered the voting age from 21 to 18 and introduced Automatic Voter Registration (Weiss 2022). The measures were implemented prior to the 2022 general election, increasing the number of eligible voters by over 40%. A disproportionate number of these new voters were registered to districts that already had a relatively high number of voters, exacerbating the disparity in district sizes. The figure below illustrates this by arranging Malaysia’s 222 electoral districts from smallest to largest (in terms of registered voters) for both the 2018 (dark grey) and 2022 (light grey) elections. Several things are striking. First, the range in district-level electorate size has grown even larger: the largest district (303k) in 2022 had over ten times as many voters as the smallest (28k). Second, the disparities are significant even beyond the extremes: the 75th percentile district (117k) in 2022 is almost twice as large as the 25th percentile (62k). Finally, the largest increases in electorate size appear to be in districts that were already disproportionately large.

UMNO’s defeat in 2018 fundamentally altered the political dynamic between the peninsula and the East Malaysian states of Sabah and Sarawak. Specifically, major East Malaysian parties that once belonged to the BN left the coalition post-election and leveraged their seats to play a stronger role in federal-level politics. Since 2018, this has included more prominent cabinet positions, including the current Deputy Prime Minister from the Sarawak-based PBB. Notably, the manifestos from the three major coalitions contesting the 2022 election all outlined intentions to empower East Malaysia through such things as greater revenue sharing from petroleum exploitation and political empowerment (Lee 2022). 

The PH manifesto—from current Prime Minister Anwar Ibrahim’s coalition—went furthest in offering Sabah and Sarawak a 35% parliamentary seat share, a significant increase from the current 25%. This reflects demands from East Malaysian political leaders, who see the increase as integral to fulfilling the original terms of federation under the 1963 Malaysia Agreement (MA63), as well as critical to ensuring that the peninsula’s domination of politics is kept in check. It is unclear whether, how, and when this rebalance might occur, but there are signs of growing momentum in its favour.[4]

Given the political difficulty of removing seats from peninsular states, the path of least resistance is likely through adding new seats in East Malaysia. Procedurally, this can be done through a two-thirds majority parliamentary vote, which is theoretically attainable given the supermajority that Anwar’s unity government currently holds.

Assuming the number of peninsular seats remains unchanged, East Malaysia would require 33 additional seats to reach the 35% seat target. At present, the seat split between Sabah and Sarawak is 45% and 55% respectively; the electorate split is similar at 46.5% and 53.5% respectively. Assuming the new seats are divided at that proportion, Sabah and Sarawak would receive 15 and 18 new seats respectively. That would bring Sabah’s total to 40 and Sarawak’s to 49 seats. Given that existing seats in Sabah and Sarawak already tend to be smaller than their peninsular counterparts in terms of electorate size, the proposed seat additions would further elevate malapportionment.

There is real and growing urgency to this question, given the complex sequencing challenge that arises due to the redelineation exercise currently in motion for Sarawak and on the horizon for Sabah (in 2025).[5] The key question is how many seats the Electoral Commission is basing the exercise on. If it is the current number, then a resource intensive redelineation exercise would have to be re-conducted following any Parliamentary approval of new seats. If it is an expanded number (for example, the promised increase to 35% of the total), then the exercise assumes Parliamentary approval that has not yet been attained. This has further implications for redelineation of state-level seats, which are likewise highly malapportioned.[6] 


Both the UNDI18 increase in electorate size and the proposed MA63-related seat increase impact malapportionment in ways that affect political competition and representation. We now turn attention to systematically measuring the magnitude of those changes, which provides insights into their effects.

The starting point is inter-state malapportionment, in other words, the unequal distribution of seats across Malaysia’s thirteen states and three federal territories. The figure below illustrates this, comparing inter-state malapportionment in the 2018 election (light grey), 2022 election (medium grey), and under the potential MA63 plan that increases East Malaysia’s seat share to 35% (dark grey). The figure shows how many seats above or below a state has relative to its share of the total electorate. For example, in the 2018 election, Terengganu had approximately 5% of Malaysia’s electorate but only 3.6% of seats, making its voters underrepresented in parliament: based on its electorate size, it had 3 seats too few, as indicated by the -3 value. In short, the figure captures how over- or underrepresented states are, relative to the size of their electorate.

Three states stand out. Sabah and Sarawak are already significantly overrepresented in parliament relative to their electorate size: Sabah had approximately 7 seats above what the size of its electorate called for in 2022, while Sarawak had 11 more. Should the MA63 proposal be implemented, that would increase to a surplus of 20 and 26 seats, respectively. To put that into concrete terms, the mean number of voters per district would fall from 67,575 (in 2022) to 42,235 for Sabah, and from 62,680 (in 2022) to 39,655 for Sarawak, relative to 106,040 for peninsular seats. That may be justifiable given their unique position in the federation and the many features that continue to make them distinct. There is little clear justification, however, for Selangor being so vastly underrepresented: it had 14 and 17 seats too few in 2018 and 2022 based on its number of voters; this would climb to a deficit of 22 seats should the MA63 proposal be implemented.[7] That amounts to a mean number of 167,175 voters per district in 2022. In short, the weight of one East Malaysian voter would be approximately four times that of a voter in Selangor.

There is substantial malapportionment of federal seats within the states as well. The figure below captures the number of voters in each district (left columns are from 2018, right columns are from 2022) for each state and federal territory. As is clear, the UNDI18 reforms and natural population growth increased the size of nearly all districts, but the effect—visible both as a general upward shift and the greater dispersion of seats—is more pronounced in some states than others. The growth of problematic mega districts is also evident. In 2018, only two districts—both in Selangor—had more than 150,000 voters. By 2022, twenty-five districts were above that threshold, now including Kedah, Perak, Negri Sembilan, Malacca, Johor, and a majority of Selangor’s districts.[8]

An international comparison helps contextualize the scale of malapportionment in Malaysia. The primary measure for malapportionment is the percentage of seats that need to be shifted from over-represented districts (with relatively small numbers of voters) to under-represented districts (with relatively large numbers of voters) in order to achieve an equal apportionment of voters across districts (Samuels and Snyder 2001). In short, higher values denote greater malapportionment. The figure below compares malapportionment in several high-income democracies—which Malaysia seeks to join—and regional counterparts to Malaysia in 2018, 2022, and under the MA63 35% proposal.[9]

As anticipated, the UNDI18 reforms did increase malapportionment between 2018 and 2022, but against the backdrop of already very pronounced levels, this increase is modest in scale. Implementing the MA63 proposal without addressing existing malapportionment would have a far more substantial effect. Regardless, the primary conclusion is that under all three conditions, malapportionment in Malaysia is considerably higher than in counterparts, with the exception of Myanmar (which based its electoral districts primarily on colonial-era administrative boundaries). This is significant, given the evidence from around the world that malapportionment has pernicious effects on a range of important matters including governance, economic development, conflict, and voter motivations.


Malapportionment in Malaysia is fundamentally a political issue. The founding 1957 Constitution called for constituencies to contain a nearly equal number of voters, with some deviation—limited to no more than 15%—to account for differences in population density, means of communication, and community composition. That limit was relaxed in 1962 and repealed entirely in 1973, paving the way for the current significant disparities. Indeed, each redelineation before 2016 saw the addition of new seats, typically allocated disproportionately to areas under the BN’s control (Chacko 2019).

This pattern of redelineation contributed to the BN’s dominance and supported a (generally unspoken) view that malapportionment provides additional assurance of Malay-Muslim political dominance. Consequently, reforms that mitigate malapportionment are sometimes cast as ploys to empower ethnic Chinese, particularly the DAP. For example, in mid-2019, UMNO’s president Zahid Hamidi suggested the DAP’s interests in redelineation were driven by a desire to gain more seats, which would be unfavourable to Malays.[10] More recently, former Selangor UMNO chief Noh Omar warned while campaigning for the PN that redelineation would be favourable to the DAP, would reduce the number of Malay-majority seats, and might even lead to a DAP prime minister.[11]

The narrative that the DAP would be the sole beneficiary of more equal apportionment is not reflected in more systematic analyses. That is because today’s malapportionment reflects not current party strengths and alignments, but rather party strengths and alignments at the time of previous redelineations, which were conducted under BN domination. The main implication is that parties that were historically associated with the BN tended to win smaller seats in 2022, while parties historically opposed to the BN tended to win larger seats. Given the comprehensive fragmentation of Malaysia’s party system relative to the era of BN dominance, that no longer cleanly aligns with current coalition structures.

The figure below shows the electorate size of districts won by major parties (or coalitions in East Malaysia) in 2022. The middle line of each box indicates the median district, while the upper and lower bounds of the box indicate the 25th and 75th quartiles, and the dots indicate outliers. For example, the median district won by UMNO had approximately 68k voters (54k and 79k respectively for the 25th and 75th percentiles), while its largest seat has 133k voters.

The distribution is striking. On the peninsula, small seats were won primarily by UMNO and Bersatu, despite them being bitter rivals in 2022 campaigning. This reflects Bersatu’s status as essentially an UMNO-clone party, at least initially comprised primarily of former UMNO elites with existing ties in over-represented areas. By contrast, PAS’s median district had 106k voters (83k and 116k at 25th/75th percentiles), significantly larger than their bumiputera rivals and reflective of their historical position as an opposition party. In fact, excluding a small number of outlier mega districts, PAS and DAP districts are quite similar in terms of size, especially in comparison to the smaller UMNO, Bersatu, or East Malaysian districts. On the high end of the distribution are PKR and Amanah districts, both of which are not only historically oppositional to the BN, but also primarily Malay-oriented. This underscores a related key point: (typically large) urban districts are now often more diverse—and more Malay—than in earlier decades, further undermining the narrative that malapportionment is primarily an ethnic issue. In fact, when controlling for party and geographic factors, an OLS regression analysis finds no evidence for an independent effect of ethnic composition on district size.[12]

Two overarching conclusions emerge from this brief study. Malapportionment in Malaysia, which was already high from a comparative perspective, increased modestly through the 2019 UNDI18 constitutional amendment and would grow significantly greater if a proposed seat increase for East Malaysia is implemented. Given the many pernicious distortions associated with malapportionment, this is a concern for issues ranging from governance to development and political polarization. Even if the unique relationship between West and East Malaysia justifies the aforementioned increase, there is no clear justification for the considerable inter- and intra-state malapportionment on the peninsula. That leads to the second conclusion: given the fragmentation of Malaysia’s party system, the simple race-based narratives around malapportionment and redistricting are no longer empirically substantiated. On the contrary, a Malay-Muslim party such as PAS has potentially as much to gain from reducing malapportionment as does its Chinese-majority rival DAP. Given that the obstacles to reducing malapportionment are ultimately political rather than technical, updating assumptions about the potential effects of reform could generate the cross-party support to see it through.


Bhavnani, Rikhil. 2021. “The effects of malapportionment on economic development”. PLoS ONE, 16(12): e0259150.

Chacko, Danesh Prakash. 2019. “Winning Elections by Rigging Borders? Barisan Nasional’s Brazen, and Failed, Attempt”. In Hutchinson and Lee (eds), The Defeat of Barisan Nasional: Missed Signs or Late Surge? Singapore: ISEAS – Yusof Ishak Institute.

Chai, James. 2022. “Bigger Constituencies, Lesser Political Clout”. ISEAS Fulcrum, no. 175.

Daxecker, Ursula. 2020. “Unequal votes, unequal violence: Malapportionment and election violence in India”. Journal of Peace Research, 57(1): 156-170.

Lee Hwok Aun. 2022. “Malaysia’s GE-15 Manifestos: Wading Through a Flood of Offerings”, ISEAS Perspective, no. 113.

Lee Hwok Aun. 2023. “Will UMNO’s Mutant Electoral Map Bite Pakatan Harapan?” ISEAS Fulcrum, no. 177.

Lim Hong Hai. 2002. “Electoral Politics in Malaysia: ‘Managing’ Elections in a Plural Society”. In Croissant, Bruns and John (eds), Electoral Politics in Southeast and East Asia, Singapore: Friedrich Ebert Stiftung.

Ong Kian Ming, Yuko Kasuya, and Kora Mori. 2017. “Malapportionment and Democracy: A Curvilinear Relationship”. Electoral Studies, 49: 118-127.

Ostwald, Kai. 2017. “Malaysia’s Electoral Process: The Methods and Costs of Perpetuating UMNO Rule”. ISEAS Trends, no. 19.

Ostwald, Kai. 2023. “The Politics of Malapportionment and Electoral Reform in a Dominant-Party Regime”. In Ting and Horowitz (eds) Electoral Reform and Democracy in Malaysia, Copenhagen: NIAS Press.

Ostwald, Kai, and Constant Courtin. 2020. “Malapportionment in Myanmar’s Elections: A Slumbering Menace”. Contemporary Southeast Asia, 42(2): 145-173.

Samuels, David, and Richard Snyder. 2001. “The Value of a Vote: Malapportionment in Comparative Perspective”. British Journal of Political Science, 31(4): 651-671.

Tindak Malaysia. 2023. “Persempadanan untuk Sarawak”, available at: https://www.tindakmalaysia.org/persempadanan/sarawak_redelineation

Ting, Helen, and Donald Horowitz (eds). 2023. Electoral Reform and Democracy in Malaysia, NIAS Press.

Washida, Hidekuni. 2019. Distributive Politics in Malaysia: Maintaining Authoritarian Party Dominance. Routledge.

Weiss, Meredith. 2022. “Can Youth Save Malaysia’s Democracy?” RSIS Working Paper, no. 337.

Wong Chin Huat. 2018. “Constituency Delimitation and Electoral Authoritarianism in Malaysia”. The Round Table, 107(1): 67-80.


For endnotes, please refer to the original pdf document.

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