[x]

It's easy living in a republic to overestimate the vices of elected politicians and ignore the vices that kings and royal governments had in the real days of monarchy. What kings did to maintain their family income streams wasn't necessarily what their subjects regarded as being in their own best interest (and of course, some kings brought their countries close to ruin with their wars and extravagances). It took representative institutions to teach kings that the average person and his or her desires might have a value in their calculation.

Even bad kings are nudged in the right direction by the necessity to avoid a revolution, while even good politicians are nudged into the wrong direction by the necessity to get elected.

Unfortunately, insecurity of thrones can nudge bad kings to be even worse -- to become all the more oppressive in the fear that their power is threatened. This is a temptation that is less common in republics than in monarchies or dictatorships. For a public official to know that he will be out of office in four years isn't necessarily a bad thing.

A lot depends on the wider cultural context. Comparing monarchy under the best circumstances to representative governments under the worst circumstances is a crooked game.

[annalex]

I am not comparing any particular monarchy to any particular republic, let alone under disparate circumstances. For a thousand years, we've seen bad monarchs and good monarchs, yet the level of taxation and appetite for wars remained pretty much a constant. Enter protestantism and elected national government, and in 4-5 centuries we have an uninterrupted expansion of government and, the latest innovation, total war.