Mencius Moldbug once opined that for a westerner to not believe in democracy in the 21st century is somewhat akin to not believing in God in the 18th century - not so much in terms of the persecution, but in terms of how much it makes you an outlier relative to respectable opinion.
Most people who get all misty-eyed when election day rolls around tend to rarely enunciate why they think democracy is such a good thing, for much the same reasons that Christians in 1700 rarely described why Christianity was a good thing. But the broadest arguments fit into two camps.
The first is that democracy is an instrumental good - voting generally, and universal suffrage specifically, are ways to ensure peaceful good government. Voting itself is neither good nor bad, but it produces much better governments than non-democratic procedures.
The second is that democracy is an inherent good. Having people collectively decide their leaders on a regular basis is the morally correct thing to do, and participating in this process should make one feel virtuous.
I can sympathise with the former argument, although I think it needs some obvious qualifications.
I cannot really believe in the latter argument any more.
In the first place, it seems that the univariate comparison between western democratic countries and third world non-democratic countries vastly overstates the treatment effect of democracy. This is an enormously complicated empirical question that the development economists war over viciously. But even just in terms of the anecdotal discourse, the democracy boosters never seem to consider the harder cases. I'm not even talking about the cases like Singapore or Dubai, which they tend to wave away as despotic, if prosperous. But was the Austrian empire ca. 1900 a despotic and terrible place to live? Hardly. By any measure of its cultural, scientific or literary output, or just general standards of living, it seemed quite pleasant indeed for the time, although it certainly wasn't democratic. Or for a modern example, would Lichtenstein be meaningfully improved by transforming it to a democracy? It's hard to see how.
Democracy boosters also never seem to want to talk much about the first world cases where democracy is receding. Quick, name an important EU-wide decision made in the last few years that was decided by anything like a popular vote! No rush, I'll go and get a coffee and check up on you when I get back. Are you railing against the EU? Maybe for their economic policy, but what about their internal governance? I don't think so.
I think there are at least two good arguments for democracy as an instrumental good. The first is the analysts consensus forecast problem - the median value of the forecasts from lots of independent analysts tends to be more accurate than the forecasts of most individual analysts. If lots of people all estimate what they think is best for the country and vote on it, the variance of the mean of our estimates is likely much lower than the variance of any one individual. So a democratic process is less likely to screw up by picking an oddball policy.
The problem arises when people aren't voting based on what they think is in the country's interests, but their own. If 51% of people get together by voting to expropriate the remaining 49% (which seems like a fair description of the west today), it's hard to see how the analysts consensus forecast improves this.
The second is the idea of increasing popular support - democracy makes people feel they have a stake in the outcome and a way to vent their grievances, hence there is less civil disruption and fewer coups. I think this definitely has a value, but then again absolute monarchies used to be quite popular at times too, especially when they had a good king (although they'd be highly unpopular now. Again, except Lichtenstein).
But if democracy is justified as an instrumental good, it's surprising how rarely people make the obvious qualifications - that its value will depend greatly on who is voting, and what they're voting for. If the people voting are mainly fools, madmen or thugs, I don't expect the ballot box to transform them into Thomas Jeffersons. If you vote for Hamas, you will get Hamas.
This leads us to the limited moral argument for democracy - that even in the case of bad outcomes, people at least get what they deserve on average. We'll put aside the case of whether the minority getting expropriated deserves their fate for their inability to stop the majority. By this rationale, the Coptic Christians are now being 'deservedly' hounded out of Egypt, just like the Christians were 'deservedly' hounded out of Iraq.
But more generally, should we celebrate when societies are transformed from undeserved good governance to deserved poor governance? Rhodesia was a racist semi-democratic state with a functioning civil society whose benefits flowed mainly to the whites, but whose level of growth was pretty good. When this transitioned to the fully-democratic (at least initially) Zimbabwe, what resulted may or may not be considered less racist (it depends on how you score the massive violence against white farmers), but it's a basket case society that has ruined and impoverished nearly everybody, black and white alike, outside of a tiny ruling elite. So celebrate! They're now 'deservedly' reliant on foreign food aid instead of exporting food to the world.
You see the problem?
Of course, the true believers think that democracy and voting have a more basic inherent moral quality - it's just the right thing to do.
You cannot reason out any system of morality without axioms, so there's not really much to dispute in this statement. I disagree, but your mileage may vary. We are still, however, entitled to ask what shadow value you place on this moral good relative to other moral goods. In other words, how much ruin in Zimbabwe are you willing to tolerate for the fact that they now have universal suffrage, instead of restricted suffrage?
I value the rule of law, and peaceful stable societies. To the extent that democracy produces this, great! To the extent that democracy destroys this, then a pox on democracy.
In the west today, it seems about a zero NPV proposition. Like all NPV calculations, it depends on what the alternative is. Transitioning from modern Britain to North Korea would be a huge step backwards, but is that really the relevant counterfactual? Europe is slowly becoming less democratic each day and nobody seems to much notice or care.
To the extent that democracy works in the west, it seems mainly because the west has cultural values that support peaceful, stable government, and they vote accordingly. I celebrate this fact, but I think it would lead to nearly equally good outcomes if they didn't vote.
This doesn't fit neatly on a sticker that you can put on your chest after leaving the polling booth. Then again, not much sensible advice ever does.