The Curious Case of Thailand's Malapportioned Party List System
By Allen Hicken and Bangkok Pundit
This post is co-authored and cross-posted with Bangkok Pundit.
Picture: Bangkok old parliament
Source: Wikipedia Commons
In a series of posts we have been examining the potential effects of the electoral reforms being considered by the junta (here, here and here). In recent weeks some of the details have begun to filter out from the CDC and the EC about how the new system will be organized (for details see reports by Matichon (screen shot), ASTV Manager, Bangkok Post, Post Today, and ASTV Manager).
Things could still change, but according to these sources here is what the CDC is proposal is likely to consist of:
Mixed-member Proportional System. As anticipated the CDC appears primed to adopt a German-style mixed-member proportional system (see our earlier analysis of MMP here) with 250 constituency seats and between 200-220 list seats.
Low/No Thresholds for the Party List. Recent reports seem to suggest that the party list election will either not make use of any threshold, or use a very low threshold of .5% (ASTV Manager). We will take a look at the practical effects of this very low threshold in a future post.
6 regions for the party list. Rather than rely on the same 8 regions used in the 2007 election, the CDC and EC are proposing the creation of 6 new regions for the purposes of the party list election. We focus on these 6 regions in the remainder of this post.
Table 1 summarized the provincial breakdown by region. The regions are fairly equal in size, with the South the smallest with a population of nearly 10.3 million, and the Upper Central Region is the largest with 11.4 million. The number of constituency seats assigned to each region is largely proportional to their size, as Table 2 shows. This reflects the way constituency seats are awarded. Seats are allocated by province, with one seat for every 260,499 persons. (Click here for a break down of the number of seats per province).
Population data as of end of 2014 obtained from: http://www.ratchakitcha.soc.go.th/DATA/PDF/2558/E/049/11.PDF
The proportionality of the constituency seats across the 6 regions stands in sharp contrast to the way party list tier seats are allocated. Table 3 displays the party list seats by region, as currently proposed. Unlike the relatively fair and equal distribution of constituency seats, the distribution of party list seats is highly malapportioned. This goes against Thailand admirable track record of historically having one of the most fairly proportioned electoral systems in the world (see this post for more details). However, if the reform is put into effect as proposed Thailand’s party list tier would rank as one of the most malapportioned systems in the world.
Figure 1 gives another view of the malapportionment in the party list. Two regions are slated to receive many more seats than their population would warrant—the Upper Central Region and the Lower Northeast. The North, by contrast, receives barely half of the seats one would expect given its population, and the Upper Northeast and Lower Central Regions are under-represented to a lesser degree. In the Upper Central region there is one party list seat for every 228,093 voters, while by contrast, there is one seat for every 580,206 Northern voters. If this proposal is implemented voters in the Upper Central Region will, in effect, count as 2.5 times more valuable than their fellow citizens in the North.
Our next post will look connection between how the party list has been organized and partisan patterns in past and future elections.
 Using Samuels and Snyder’s (2010) malapportionment score the malapportionment score for the party list tier is 12.8%, meaning that nearly 13 percent of the party list tiers are unfairly apportioned.