It is not the case that electoral systems are ultimately a choice between fair representation and political stability.
What does the study tell us?
Comprehensive analysis spanning five decades and 17 established western parliamentary democracies reveals that Proportional Representation (PR), rather than an impediment to political stability, can if anything facilitate a more stable politics.
The comparative study, spanning the fifty years from 1973 to 2022, examined ten crucial indices of political stability, including parliamentary term completion rates, ministerial turnover, and party tenure in government.
The results are striking: on average, across eight of the ten measures, countries with PR systems have outperformed those using majoritarian systems (see Figure 1).
More compellingly still, when comparing individual countries, PR users come top in nine out of the ten measures, and provide 73% of the top 30 performers.
New Zealand and proportional representation
New Zealand’s smooth transition from FPTP to Mixed-Member PR illustrates the central point of the report for a UK audience (see Figure 2): the data shows that PR’s introduction in New Zealand has not led to the chaos electoral reform opponents predicted.
In fact, in six of the ten measures, the period since 1996 has demonstrated slightly greater political stability than the preceding two decades.
What are electoral systems impacted by?
As the report makes clear, it is the minimal difference across the two periods that is most telling: rather than electoral systems, the political stability of a country is best explained by cultural or wider institutional differences.
Nevertheless, this new study unequivocally refutes the claim that PR systems inherently sacrifice stability for fair representation.
Further, it suggests that, whether causal or not, it has been PR users who have been the most stable of the 17 sample countries, with nearly all proportional democracies reaching what would be viewed as a reasonable level of stability.
A comment from the study’s author
Dylan Difford, the study’s author, said:
“This report categorically debunks the idea that introducing PR would inevitably lead to more political instability. Contrary to the claims of opponents of electoral reform, the experiences of other comparable countries clearly show that you can have better representation without succumbing to political chaos.
“Choosing PR does not mean sacrificing stability – instead the choice is more whether you can tolerate millions of people’s votes having no impact on the outcome of elections.”
To come up with a measure for overall political stability, the study examined government durability (accounting for changes in prime ministers), the partisan composition of government, and election frequency. According to the findings, PR-using countries, including Germany, Luxembourg and Switzerland, demonstrated the best government durability in the last fifty years.
This is the pattern reproduced across the board – countries that use PR are clearly capable of the highest levels of political stability, more so than those that use majoritarian systems.
The data demonstrates that it is a widely-held misconception to think that more frequent prime ministerial turnover is the fault of proportional systems.
Italy, as is often highlighted by critics of PR, is actually less representative of proportional democracies than Germany, the country of 16-year Chancellors Kohl and Merkel. Indeed, the longest average tenures in the sample countries have come in those that use a form of PR.
Likewise, when it comes to early elections, the data dispels any idea that PR inevitably leads to regular governability crises that necessitate frequent new votes.
Finland, Luxembourg, Norway, Sweden, and Switzerland – all countries that use PR – are less likely to hold snap elections than First Past the Post (FPTP) users such as the UK and Canada.
While governments may on average be formed more quickly in majoritarian systems, this is often a cultural choice, as coalitions can be swiftly established with the appropriate political will, as has been seen in the UK.
Additionally, the relative infrequency of changes in the party of majoritarian governments is offset by the greater ideological stability between governments in PR countries, the report observes.
Overall, the report notes that it is not credible to suggest that the UK would inherently become less politically stable if it adopted a PR voting system.
The data does not reveal a causal link between fairer election results and higher levels of political instability, with the variations within both categories of voting systems – whether in relation to early elections, governing party alternation, or prime ministerial turnover – clearly suggesting that political culture and institutional differences, not the presence or absence of PR, bear a more significant influence on political stability.