Is it because they are "young democracies/countries" (compared to the US and the UK) and at the time of their establishment there were more people with different political views and therefore the proportional voting system was simply more suitable for them?
First, I think that the question is not very well posed.
Is it because they are "young democracies/countries" (compared to the US and the UK)
What is a "young democracy"? The Athenian democracy in antiquity, the Republic of Venice or Switzerland are much older than the US or democracy in the UK. The UK has a long democratic tradition with a Magna Charta and a Parliament, but it was still the king who ruled. Occasionally he had to summon the Commons, when he didn't have enough money for war.
By the way, the idea that the king had unlimited power and the populace had no say in medieval Europe is completely wrong. Royal power was limited by statutes and the king often had to convoke some kind of assembly to gather support. In Spain, these assemblies were called Cortes, in Germany Reichstag or Landtag and in France Estates General. England wasn't exceptional in having commoners as representatives either, there were commoners in the 13th century Cortes and the Estates General.
and at the time of their establishment there were more people with different political views and therefore the proportional voting system was simply more suitable for them?
The US had a population of more than 3 million people, when it became independent. That's more than quite a few democracies with proportional voting in Europe and the world have today. And I don't see why proportional voting should be unsuitable for smaller countries - unless a polity is so small that a parliament becomes unnecessary or too burdensome.
Still, I agree that age plays a role. Most constitutions, which are currently in vigor in Europe, were written in the 20th century. When the US constitution was written, time wasn't ripe yet. There was no existing country that could serve as a model, no mass newspapers, important travel times and probably many other obstacles.
However, the idea that the people should be represented proportionally existed:
- It should be in miniature, an exact portrait of the people at large. It should think, feel, reason, and act like them. That it may be the interest of this Assembly to do strict justice at all times, it should be an equal representation, or in other words equal interest among the people should have equal interest in it. (John Adams, Thoughts on Government, 1776)
- A representative body is to the nation what a chart is for the physical configuration of its soil: in all its parts, and as a whole, the representative body should at all times present a reduced picture of the people, their opinions, aspirations, and wishes, and that presentation should bear the relative proportion to the original precisely. (Mirabeau in a speech at the Assembly of Provence, 1789)
Some European countries:
- UK: No proportional representation. Much of the political system has a very long tradition.
- France: No proportional representation. Actually, proportional representation was used during the Fourth Republic (after the Second World War), but it was abandoned in 1958.
- Germany: Partially proportional representation with constituency candidates and a party list. The constitution dates from 1948 - designed under important American and British influence.
- Spain: Proportional representation. The constitution of 1978 entered in force after the death of dictator Franco.
- Netherlands: Proportional representation. The current constitution derives from a document written in 1815. Proportional representation was introduced in 1917.
- Poland: Proportional representation. The current constitution entered in force in 1997. Unfortunately, I don't know about the voting system under the first post-Communist constitution and during Communism. (My guess is that it had already been proportional, even if the elections were far from free.)
Ultimately, let's have a look at a world map (Source: Wikipedia article on "Electoral System)":
If you look at Africa and Asia, you see that "younger" countries do not automatically adopt proportional voting, even if much of South America has done so. At least in some cases, colonial tradition may play a role (i.e., former British colonies like India, Nigeria, Kenya or Botswana).
- (Red) First past the post (FPTP) (44 entries)
- (Maroon) Two-round system (TRS) (23 entries)
- (Puce) Instant-runoff voting (IRV) (2 entries)
Multi-member constituencies, majoritarian:
(Dark blue) Majority bonus system (MBS) (2 entries)
(Orange) Block voting (BV) or mixed FPTP and BV (14 entries)
(Brown) Party block voting (PBV) or mixed FPTP and PBV (3 entries)
(Yellow) Single non-transferable vote (SNTV) or mixed FPTP and SNTV (3 entries)
(Citron) Modified cumulative voting (1 entry)
(Lime) Modified Borda count (1 entry)
Multi-member constituencies, proportional:
- (Light blue) Party-list proportional representation (party-list PR) (80 entries)
- (Mint) Single transferable vote (2 entries)
Mixed majoritarian and proportional:
- (Purple) Mixed-member proportional representation (party-list PR and FPTP) (6 entries)
- (Lavender) Mixed-member proportional representation (party-list PR and TRS) (1 entry)
- (Dark pink) Parallel voting (party-list PR and FPTP) (23 entries)
- (Persian rose) Parallel voting (party-list PR and TRS) (1 entry)
- (Fuchsia) Parallel voting (party-list PR and BV or PBV) (2 entries)
- (Light deep pink) Parallel voting (party-list PR and SNTV) (1 entry)
No relevant electoral system information:
- (Dark grey) No direct elections (9 entries)
- (Light grey) No information (4 entries)
While it is the case today that most European countries have a form of proportional representation, that apparently was notthe case when they first introduced democracy/elections, as described in a paper by Jonathan Rodden, which says
During the period from around 1890 to 1920, most European countries dramatically expanded the franchise to include the working class, abolished plural voting for the wealthy, and reduced the power of the landed gentry in undemocratic upper legislative chambers. During the same period, the vast majority of these countries replaced electoral systems featuring a large number of small, winner-take-all districts with some version of proportional representation.
In other words, the question could/should be asked as: why did most of Europe reform their systems but UK, US, (or France) did not?
The last paper I quoted discusses various theories why a proportional representation system reform swept through most of Europe. Among the chief hypotheses:
- Braunias (1932) proposed that in most European countries after WWI this was a strategy of the elite to prevent the socialists from taking power after voting rights could no longer be denied to the majority of the population (who were poor).
- More recent views such as that of Alesina and Glaeser (2004) is of a interesting coincidence of views: both the socialists and the old elite believed their interests were best served by a proportional representation in the aftermath of WWI in a number of countries, including Belgium, Sweden, and Germany. The socialists wanted proportional representation because the concentration of their supporters in urban areas translated poorly into seats under the old system(s). There's something more to said here about Liberal parties: in countries such as the UK or New Zealand where the Liberals (the "old left") did not support a proportional system at the time betting/thinking they could beat the emerging socialists/Labour in their urban constituency, they [the Liberals] were soon marginalized, leaving on the right/Conservatives and the socialists/Labor as heavyweight political parties. (The Canadian Liberals are the only exception to this having survived the socialist challenge without a proportional system, but having substantially nudged their platform further to the left.)
You should know that this is an active area of research in Political Science. Proportional representation is quite widespread in Europe. I would recommend the paper The Adoption of Proportional Representation (Leemann & Mares, 2014) which in the very first page lists the major comparative works made on the subject, and the two most common explanatory families:
Like any change in electoral rules, the adoption of proportional representation poses an immediate puzzle: why do politicians engage in risk-taking behavior and decide to replace the institutional rules on the basis of which they have been elected? Existing explanations for the reform of electoral institutions and the adoption of proportional representation cluster in two broad explanatory families, stressing either economic transformations or changes in the broader political environment as the source of political anxiety among right-wing politicians. Let us consider the larger political changes first. Both hypotheses—stressing either the rise of Social Democracy or disproportionality in the allocation of votes to seats—as determinants for demand for changes in electoral institutions can be traced back to the work of Braunias and Rokkan (Braunias 1932; see also Rokkan 1970, 157–58).
The major works listed are:
Ahmed, Amel. 2012. Democracy and the Politics of Electoral System Choice: Engineering Electoral Dominance. Cambridge: Cambridge University Press.
Benoit, Kenneth. 2004. ‘‘Models of Electoral System Change.’’ Electoral Studies 23 (3): 363–89.
Blais, Andre, Agnieszka Dobrzynska, and Indridi Indridason. 2005. ‘‘To Adopt or Not to Adopt Proportional Representation: The Politics of Institutional Choice.’’ British Journal of Political Science 35 (1): 182–90.
Boix, Carles. 1999. ‘‘Setting the Rules of the Game: The Choice of Electoral Systems in Advanced Democracies.’’ The American Political Science Review 93 (3): 609–24.
Calvo, Ernesto. 2009. ‘‘The Competitive Road to Proportional Representation. Partisan Biases and Electoral Regime Change under Increasing Party Competition.’’ World Politics 61 (2): 254–95.
Colomer, Josep M. 2005. ‘‘It’s Parties That Choose Electoral Systems (or, Duverger’s Laws Upside Down).’’ Political Studies 53 (1): 1–21.
Cusack, Thomas, Torben Iversen, and David Soskice. 2007. ‘‘Economic Interests and the Origins of Electoral Systems.’’ The American Political Science Review 101 (3): 373–91.
Kreuzer, Marcus. 2010. ‘‘Historical Knowledge and Quantitative Analysis: The Case of the Origins of Proportional Representation.’’ American Political Science Review 104 (2): 369–92.
Further this is not a static context. For example:
There is some talks of advocating the same for the UK. Particularly because parties such as the new Independent Group (former Labour MPs) might need these reforms to survive. Moreover proportional representation was implemented for European Elections in the UK (see Trends chapter at the link).
Yes, I think older democracies (the US, the UK, France) and countries that explicitly modeled their systems on those (Australia, Canada) tend to have First Past the Post, or double ballot majority rules (districtal election of representative bodies). Countries that have established their democratic constitutions more recently, and particularly after WWII, tend to have proportional ballot. Why that, I am not sure; perhaps proportional ballot is a reaction to the perceived problems of FPTP; perhaps it involves technical difficulties that were more easily solved more recently; or perhaps the older democracies were established at a time when modern political parties still did not exist, so proportional vote would not make much sense.
There is however a more recent tendency to revert to majoritary vote, or otherwise abandon pure proportionality. Minimal thresholds, mixed proportional-districtal vote, non-party lists, individual candidacies, bonuses for most voted parties, etc., seem to be on the rise for the past quarter century.