Origin of this thread was voting of law to change Brazilian from open list proportional representation to a multi-members constituency (distritão), supported by Speaker Eduardo Cunha (PMDB-RJ) and Vice President Michel Temer (PMDB-SP). Luckily this had been defeated.
Yeah. I don't know what is the best system for Brazil. I know that the use of states as multi-members constituency (distritão) is the worst one.
The system in use today, open list proportional representation, is not good because because the costs of campaigning are very high. This system means everyone against everyone, parties compete against each other, candidates of the same party compete against each other, the same candidate can have the votes in a whole state (in big states, like São Paulo, Minas Gerais and Bahia, this means very big distances). So, only very rich candidates, or candidates who receive big donations, or very famous candidates can be elected.
I think pure FPTP is not very representative.
Mixed FPTP-proportional (like in Germany) looks like good.
Proportional representation with closed party list looks like good too, but only the left-wing parties support it, so, it will never be approved.
Donations by firms should be forbidden. I think only public funds and donations by individuals should be allowed.
The opponents of the FPTP (pure and mixed) say that most of the countries use proportional representation. OK, but we can see that most of the SMALL countries use proportional representation. Big countries like Canada, USA, Mexico, India, UK, France and Germany (the last three are big according to European standards) adopt some kind of single-member constituency. Maybe, single-member constituencies fit well for big countries.
However, changing the voting system is not the magic to improve the quality of politicians of a country. In many countries there are people who consider that the system of other countries is better. In Brazil, many people unsatisfied with the proportional representation are proposing FPTP. In the UK, after the last election, many people considered that FPTP is unfair and that proportional representation could be better. In the USA, the "Fair Vote" movement is advocating for proportional representation.