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The Value of a Vote: The Effects of One Province, One Seat on Representation in Thailand

By Allen Hicken


Picture: Thai general election 2017

Source: Wikipedia Commons


Thailand is in the midst of a wholesale reform effort. The National Reform Council (NRC), selected by the coup-installed National Council for Peace and Order (NCPO), has been tasked with recommending reforms in a breathtaking array of areas, but there is no doubt a major focus will be political reform. A variety of ideas and plans are currently circulating, (including one drafted by the Ministry of Defense with the explicit endorsement of the NCPO) and more will certainly be proposed in the days and weeks to come. As expected, many are focusing on reforming the electoral system. Proposals have included the introduction of primary elections, a majority run-off system for parliamentary elections, a directly elected PM, and indirect elections for at least some legislative seats.


Recently, Chai-Anan Samudavanija, a member of the NRC,shared his views of what reforms are needed. Chai-Anan is a respected senior academic and played a prominent role in the drafting of past Thai constitutions, including the 1997 “People’s Constitution.” Among his recommendations is a move to a much smaller parliament of only 77 seats—one seat for each of Thailand’s provinces (Thailand’s last elected parliament had 500 seats). He argues that with fewer MPs there would be less corruption—a claim I will examine in a future post. Here I want to consider what the effects of such a system would be on representation and the partisan composition of parliament.


Representation and Malapportionment


One of the fundamental principles of democracy is the idea of “one person, one vote.” There are various ways this principle can be violated to the detriment of democracy, but one way this is done is by weighting the votes of citizens in some areas of the country more than the votes of citizens in another area. Political scientists use the term “malapportionment” to refer to the degree to which the share of seats for a given geographic unit deviates from its share of the population. In malapportioned systems some units are over-represented (receiving more seats than their population would warrant) and some are under-represented (receiving fewer than their population merits).


Whatever the faults, one of the virtues of Thailand’s past democratic electoral systems is that they have largely given the same weight to all votes. All votes were, in other words, treated equally, whether they came from Bueng Kan or Bangkok, Narathiwat or Nan. Political science has developed a Malapportionment Score which measures the extent to which seats are allocated to constituencies that would not otherwise receive those seats if there were no malapportionment. The score ranges from 0 to 1 with high scores corresponding to greater malapportionment. In 2011 Thailand’s Malapportionment Score was .035 for the House of Representatives. In other words, less that 4 percent of Thailand’s seats where malapportioned, making Thailand one of the most fairly apportioned democracies in the world.


Moving to a one province, one seat legislature wouldintroduce a level of malapportionment unheard of in Thai history, and at the extreme of what we see elsewhere around the world. Specifically, one province, one seat would translate into a Malapportionment Score of .26. More than a quarter of Thailand’s seats would be malapportioned under this system. In comparative terms this is a staggeringly high number for a lower chamber ofparliament. In a 2001 study Samuels and Snyder reported the Malapportionment Scores for seventy-eight countries around the world. The table below is a reproduction of their Table 4—The Twenty Most Malapportioned Cases—with the addition of Thailand under one province, one seat. Even compared to these highly malapportioned cases Thailand would top the list.


Table 1

Lower Chamber Malapportionment, Twenty Most-Malapportioned Cases



​Source: Adapted from Samuels and Snyder 2001.


The Partisan Consequences of One Province, One Seat

Would the shift to one province, one seat have a meaningful effect on the distribution of partisan power in Thailand?This is a trickier question to answer, but we can get a rough sense of what the partisan consequences would be by looking at how voters in each province cast their vote for the party list in 2011. If we assume that the party that received the most party list votes in each province would also receive the most votes in a single-seat province-wide election what would the distribution of seats have been in 2011? Table 2 shows that the biggest winner from such a change would be the Democrat Party, followed closely by Pheu Thai. The Democrats would increase their share of seats to 40.3 percent under this scenario, compared to 31.8 in 2011. Pheu Thai would also benefit under this new system—increasing its majority to just under 60 percent of legislative seats. The biggest losers under this proposed system would clearly be Thailand’s smaller parties who would fail to win a single seat in our hypothetical election.


Table 2

Seat Shares under One Province, One Seat



However, this doesn’t tell the whole story. One province, one seat gives Bangkok, with a population almost 5.7 million, the same number of seats as tiny Ranong, with less than 200,000 people. As a result, voters and votes from small provinces receive extra weight, while votes from large populous provinces are severely under-weighted.Table 3 shows the ten provinces that would be the most under-represented with the one province, one seat scheme alongside the ten provinces that would be the most over-represented. For each province I have listed the party that was the top vote-getter in the party list voting in 2011. There is a clear pattern. Eight of the ten provinces that would be the most advantaged under one province, one seat are Democrat provinces, while eight of the ten most under-represented provinces supported Pheu Thai.


Table 3

Most Over/Under Represented Provinces under One Province, One Seat