Economy, Stability, Environment, Health Care
The economy grows 1% faster with Pro Rep (highly statistically significant, https://goo.gl/e4fT71). Pro Rep produces 1 percentage point higher economic growth (which is huge) according to Carl Henrik Knutsen’s study of more than 3500 country-year observations from over 100 countries.
Pro Rep usually produces more stable governance than First-Past-The-Post. This is because Pro Rep tends to result in multi-party coalition majorities, so that policy depends on the consensus of at least two leaders rather than being at the flighty whim of a single leader.
Background & More Info:
Canadian history at the federal level shows that we do not need single-party majority control of government to get things done:
Pro Rep governments are more cautious and run up less government debt: