How New Electoral Rules Shaped the Outcome of Thailand’s Election

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How New Electoral Rules Shaped the Outcome of Thailand’s Election

The changes, which included the shift from a single to a dual ballot system, had a different impact than was generally predicted.

How New Electoral Rules Shaped the Outcome of Thailand’s Election

A Thai officer shows a ballot during vote counting at polling station in Bangkok, Thailand, Sunday, May 14, 2023.

Credit: AP Photo/Rapeephat Sitichailapa

While the opposition victory in last month’s general election in Thailand was largely due to broad disaffection with the role of the military and the crown in politics, the results were also influenced by changes to the rules by which the election was run. Many of the changes to the voting rules in the 2017 Constitution that allowed Prayut Chan-o-cha, the leader of the 2014 coup, to remain as prime minister following the 2019 election were reversed or reformed, although the key role of the military-appointed Senate in the selection of the prime minister remained.

Pre-election predictions suggested these changes would benefit the largest parties – especially the opposition Pheu Thai Party – and, given the influence of the government on Thailand’s Election Commission (EC), could particularly favor more conservative parties. In the end, however, many of these changes to the electoral rules had impacts that greatly differed from those predicted prior to the election.

Changes to the Electoral Rules

The most notable change from the 2019 election was the shift from a single to a dual ballot system. In 2019, voters received a single ballot and voted for their preferred candidate’s number; by choosing their preferred candidate in their constituency, voters were simultaneously voting for their preferred party – that of the candidate for whom they voted. With a single vote they impacted who was elected in the constituency and the selection of parliamentary candidates from “closed” party lists (lists with candidates ranked by the party in the order they will be selected). In such a system, known as mixed member proportionality, the MPs selected by the party list vote compensate for any disproportionality in the constituency vote.

However in 2023, voters could split their vote. On one ballot they voted for their preferred candidate while on another, their preferred party. In the terms of political scientists and game theorists, voters could choose their true preference for the party vote and vote strategically on the constituency vote. Voting strategically on the latter ballot might involve choosing the preferred candidate out of the top two likely highest vote-getters; voting for a candidate with little choice of winning would be considered a “wasted vote.” For example, a supporter of the conservative United Thai Nation Party (UTNP) who lived in the less conservative Northeast, could choose UTNP for the party vote, but vote for whichever front runner in their constituency they considered the “lesser of two evils.”

Dominant theories in political science predict that these changes would have helped smaller parties in 2023, because their supporters could vote for a small party with their party list vote without “wasting” it. Two structural factors, however, worked against the system benefiting smaller parties. First, the number of MPs chosen by party list was reduced from 150 in the 2019 election to just 100 in 2023, while the number of MPs chosen in constituencies increased from 350 to 400.

Second, the threshold that a party needed to meet in order to gain a party list seat was raised. This latter fact was heavily debated in parliament with smaller parties, in particular, arguing against the change. In 2019, the 150 party list seats were allocated to make the percentage of overall seats a party had in parliament roughly equal to the percentage of their overall vote. For example, in that election the Bhumjaithai party received roughly 10 percent of the vote and won 39 constituency seats. It was therefore given 12 party list seats so that its percentage of overall MPs was equal to its 10 percent of the vote.

In the same election, the opposition Future Forward Party – the predecessor of the Move Forward Party – won only 31 constituency seats but 17 percent of the vote. It was therefore given 50 party list seats so that its total number of 81 seats was roughly equal to 17 percent of all the seats. Overall, 26 parties were represented in the House (compared to 18 in 2023), with nearly half of those only winning a single seat, all by party list vote.

But for the 2023 election, the party list seats were chosen without regard to how many constituency seats a party won. The concern expressed about this change is that it would harm the chances of small parties. But, as noted above, such a system also allows voters to vote their true preference with their party list votes. UTNP, for example, won only 9.48 percent of the constituency vote and just 23, or 5.8 percent, of constituency seats, but won 12.6 percent of the party list vote, securing 13 more seats. Overall the UTNP won 7.2 percent of the seats in the House of Representatives. Somewhat ironically, Move Forward did well under the new system; the reformist party won 25 percent of the constituency vote but 28 percent of the constituency seats. It won a further 38 percent of the proportional vote giving it 39 of the 100 party list seats and 151, or 30 percent, of the overall seats.

Under the 2017 Constitution, both houses of parliament comprising the National Assembly – including the 250-member Senate appointed by the leaders of the 2014 military coup – vote for prime minister, pushing up the majority required from 251 votes to 376 votes. Had smaller parties gotten their way and the formula originally proposed for the 2023 election of dividing the total number of party list votes by all 500 seats rather than 100 was used, Move Forward, the largest party, would have received about 190 overall seats, instead of only 151, while Pheu Thai would have secured about 144, rather than 141. This would have put the two parties combined just 42 votes short of the number needed to select a prime minister, far closer than the 84 votes they need now.

Another change to the electoral system was the number of people represented by each member of parliament and the redrawing of the constituency boundaries. In early March, the court ruled that non-Thais, such as foreigners with permanent or temporary residence, would not be counted, leaving each MP now representing 162,766 Thai citizens, rather than 165,226. Eight provinces were affected by this ruling with four losing one MP, and another four gaining one.

Relatedly, several parties contested the variation in representation, with some constituencies overrepresented and others underrepresented. In response, the Supreme Administrative Court ruled that the EC had the right to draw the districts and could allow 10 percent variation in the number of Thais per MP. Additionally, some parties raised concerns with the EC’s redrawing of Bangkok, which lumped unrelated sub-districts into a single constituency rather than grouping sub-districts from the same district into a voting area. Redistricting affects voting patterns because of gerrymandering; nevertheless, Move Forward nearly swept the capital, winning all but one of Bangkok’s 33 constituencies.

Moving Forward With the Next Government

Overall, although the Move Forward Party (MFP) is clearly being considered the “winner” of the election and will get a first crack at creating a government, the Pheu Thai Party (PTP) did nearly as well. Perception matters, of course, and the perception is that the PTP did worse than expected; practically, however, it will have only 10 fewer seats in the House than the MFP. This means the PTP will insist on some important positions; it has already demanded the position of Speaker of the House, which the MFP has refused.

There are inherent tensions in the goals and philosophies of the two parties, with the newer MFP valuing its firm ideals to radically reform the Thai political landscape and the coup-weary PTP driven by a less idealistic desire for power. These contrasting goals are further complicated by the bloc’s dynamics; had the MFP scored a much larger plurality of the seats, as it likely would have under the 2019 electoral rules, they would have a stronger say in the coalition’s decision-making, but with a political ally who has nearly an equal claim to directing the bloc’s agenda, MFP will have to compromise with its PTP partner.

The opposition currently remains quite a ways off from the 376-seat threshold needed to elect MFP party leader Pita Limjaroenrat as prime minister. The six parties that signed a coalition pact with the MFP and PTP in late May contribute only 20 seats to the MFP-bloc and, along with some 19 senators who have announced their support for the coalition, leave the opposition 45 votes away from a National Assembly majority. Under the electoral rules of the previous election, the 334 seats MFP and PTP would likely have won combined with these 19 senators would have left them only needing 23 more coalition members.

As in past elections, the opposition face challenges on multiple fronts, including the legal threat of dissolution, the EC’s scrutiny, and the veto of the military-backed Senate. And while following his resounding defeat Prayut made statements supporting the voters’ right to determine their leadership, Thailand’s history of 19 coups and 20 constitutions in less than a century loom over all efforts to form a government and lead effectively. Although conservative complaints to the EC against the MFP and PTP have largely been dropped, politically motivated court decisions used to oust anti-establishment parties from power – such as the removal of Prime Minister Samak Sundaravej from office in 2008 – are not yet out of the question. Overcoming these high hurdles makes inter-bloc unity all the more important for the MFP’s newly-formed coalition.