I think you should be looking more at question of dilution of power. Concentrating power is hands of a one or handful of people makes the system very dependent on the person holding that power. I would propose republics/nominal monarchies with head of state only having reserve powers, are more stable and produce better government than hands-on head-of-states.
Just because a country has been under a monarchy for a very long time, doesnt mean that it was “stable”. Look for “dynastic change” in the line. Often rather violent, but one way to get rid of a bad/unpopular ruler. Republics makes it easier to dump the head of state without violence so that is improvement.
I value the diluted power of parlimentary democracies, with the select committees and multiple reading of bills, but I would struggle to find empirical data to support that. How do you define “politcal performance” or “leader competence” in measurable ways? How do you evaluate the quality of political decisions? How a country performs economically or militarily is dependent of a myriad of factors (including luck), many outside the control of the government. Governments will claim credit for whatever went well, and drop shoulders on anything that didnt—how do you objectivity assess those claims? Eg how much of the USA current position due to good governance or how much due to being a resource-rich country colonised at time when industrial revolution was able to exploit those resources?
I think you should be looking more at question of dilution of power. Concentrating power is hands of a one or handful of people makes the system very dependent on the person holding that power. I would propose republics/nominal monarchies with head of state only having reserve powers, are more stable and produce better government than hands-on head-of-states.
Just because a country has been under a monarchy for a very long time, doesnt mean that it was “stable”. Look for “dynastic change” in the line. Often rather violent, but one way to get rid of a bad/unpopular ruler. Republics makes it easier to dump the head of state without violence so that is improvement.
I value the diluted power of parlimentary democracies, with the select committees and multiple reading of bills, but I would struggle to find empirical data to support that. How do you define “politcal performance” or “leader competence” in measurable ways? How do you evaluate the quality of political decisions? How a country performs economically or militarily is dependent of a myriad of factors (including luck), many outside the control of the government. Governments will claim credit for whatever went well, and drop shoulders on anything that didnt—how do you objectivity assess those claims? Eg how much of the USA current position due to good governance or how much due to being a resource-rich country colonised at time when industrial revolution was able to exploit those resources?