During 2000-2050, the world will face several crises. These include: the end of cheap oil (update: fracking & tar sands have postponed the oil crisis somewhat), various "fossil water" resources running out, global fisheries species collapse, USA or Japan federal bankruptcy, overpopulation, nuclear and bioweapons proliferation, and climate change. These could easily bring about the "end of modern civilization." Far as I can see, world population and consumption levels are already well beyond what can be supported with renewable resources, therefore a population decline is inevitable.
In view of that, the world needs to make good decisions. But the "decision making algorithm for the world" is (to a close approximation, with the USA the only "superpower") the same as "the USA's horrible voting system."
That isn't good enough. Range voting is a far better decision-making algorithm.
1. Suppose the USA, by adopting range voting and thus making better decisions, lowers the risk of a 2-billion population crash in 50 years, by 5%. I consider this a conservative estimate. That is, in expectation, 100,000,000 lives saved in 50 years, which is 2,000,000 per year, or 5500 per day, or 230 per hour, or 1 life saved every 16 seconds.
So as you can see, every minute counts.
2. Didn't buy that estimate? Another way to get similar numbers is to consider the fact that range voting democracy is expected to be a comparably big improvement over plurality-voting democracy, as the latter was over non-democracy. (E.g. see paper #96 here, or this.) The USA, which often proclaims itself the world's leading democracy, has life expectancy 77.6 years; meanwhile China, the world's leading non-democracy, has 71 years (according to the UN; 69 for men, 73 for women), vs. Taiwan 77.4. Australia (democracy): 80.3 years, versus the Congo (largest country in Africa, located about same latitude, with comparable physical size, and probably with better climate and natural resources, but has not been a democracy until, perhaps, just now – it just held its first elections in the modern era, in 2006): 53 years. Germany: Life expectancy in former East Germany jumped from 76 to 81 for women and from 69 to 75 for men since reunification (78.6 Germany-wide average as of 2006). Or compare N. and S.Korea. So, all in all, it appears that democracies have higher life expectancy by approximately 1/7 of a life. So with world population now 6.6 billion, we again estimate that implementing range voting worldwide will save about a billion lives (just out of today's lives).
3. Still unconvinced and want another estimate? Suppose adopting RV raises the world GNP by 1%. (Economic estimates.) We won't even bother to assume 1% per year; we'll merely assume a 1% one-time rise to get a very conservative estimate.) Converting "lives" to "money" by multiplying by the average amount of money a person generates in a life, that'd be saving 65 million lives, which if the changeover to RV took 32 years, would again be about 5500 lives saved per day.
4. Also Rummel's estimate is of the same order. (Rummel's "power kills" web site re the same topic.)
5. The following book-length studies all are about how much democracy is worth in terms of either lives and money:
Rummel concludes with these two quotes summarizing his lifetime of award-winning research into war, democracy, and genocide:
6. Need more concreteness and less abstraction? Consider the 2000 US presidential race (Bush vs Gore vs Nader), won by G.W.Bush. With range, approval, instant runoff voting, etc (almost every voting system other than the one used) or if we'd got rid of the electoral college, A.Gore would have won instead. How many lives would that have saved? Well, this study (pdf) published in the peer-reviewed medical journal The Lancet, estimated 655000 were killed in the Iraq War (which Bush started). Further, the cost of paying Bush's US budget debt of ≈$1 trillion caused by that war, is (converting from money to lives worth of labor at $3 million per life) 300,000 lives; but see this for estimate by Economics Nobelist and former World Bank head J.Stiglitz that the cost will really be more like $3 trillion. So as an estimate, range voting in just that one election alone would have saved about a million lives, i.e. (averaged over Bush's 8-year term) 342 per day, i.e. one life every 4 minutes.
Of course, there is some small chance that Gore still would have started that war (or something even worse) so this is not a completely sure thing. And there were other things (besides range voting) which also might have changed the winner to Gore. (Also, the "best" winner might have been Nader, and after enough use of superior voting systems he might have won.) I'm saying this is just one random effect in just one country, which in expectation is pretty large. Add up all such effects in all countries in all years, and you get a much larger and surer expectation.
Need another example? I'm (re)writing this in October 2009. At present the top issue (according to the News Media) in the USA is the health-policy debate. A Harvard medical study (their press release) cited in that debate found that people in the USA without health insurance had a 40% higher risk of death, with the net result being that the USA's costly, inefficient, and partial health insurance system was causing 45000 excess USA deaths per year, i.e. about one every 12 minutes. Meanwhile a Thomson Reuters report released 26 October 2009 found "the U.S. healthcare system wastes between $505 billion and $850 billion every year," which at $3.5 million per USA-average life (based on 2009 USA GDP, life expectancy, and population) is equivalent to 144-to-243 thousand deaths. One could speculate that perhaps if we'd had range voting, the USA would already have had a better health insurance system for years. But in any event, this death toll caused by lack of health insurance is clearly of the same order of magnitude as the death toll we have estimated is caused by lack of range voting. Get the picture? The "most important issue" in the USA today (according to media; and we agree it is quite important) is comparably important to the apparently-far-simpler issue of getting range voting (and the media is paying nearly zero attention to the latter!).
7. There are exactly two countries in Europe with what I consider to be an "advanced democratic design" namely Switzerland and Ireland. Both started out poor, riven by ethnic/religious strife, occupied by invaders, and in the case of Switzerland it is landlocked with inhospitable terrain and virtually no natural resources. At the time, they were about the worst places to be in Europe. But they adopted advanced democracy. (Ireland: Proportional Representation via Hare/Droop reweighted STV voting. Switzerland: unparalleled strong "direct democracy" and decentralized power elements.) So fast-forward to the present day (2005). Switzerland and Ireland are now among the most successful countries in Europe and the world in terms of GDP/capita despite their poor starts and inherent disadvantages. Indeed, a good approximate picture of Europe circa 2005 is: These two advanced democracies are at the top of the economic and life-quality heap, along with Norway (a non-advanced-type democracy, but it has oil). In the middle are the ordinary democracies. At the bottom are the non-democracies (or those which were until recently). See a trend?
(One could also add Australia, which also has improved a heck of a lot since it adopted an advanced democratic design, but I'm leaving it out since it is stand-alone, as opposed to Switzerland and Ireland which, since inside the European mileau, can be compared with all the others.) I do not actually consider this to be convincing proof because Ireland and Switzerland are only 2 datapoints. But still, adopt a gambler's attitude: "expectation value." It is a good bet. I mean, if you can make a good bet that something will improve the world by as much as Switzerland & Ireland got improved... I'd make it. Especially since the downside (if the bet fails) is basically nonexistent.
Compare with other "good causes": First, many "other" Good Causes such as preventing wars (history basically indicates that wars between democracies are rare or nonexistent), ending the "drug war," decreasing corporate domination, preventing climate change (current US democracy is not interested), increasing freedom, increasing education, and decreasing "lapdog" media which block important views, all would, in fact, be partially or totally cured automatically with range voting.
Second, there are very few causes out there with this much "bang for the buck." Examine the numbers yourself. I do not believe religious causes can compete. Disaster relief cannot compete (in the long term; for large disasters in the short term, it can). Curing diseases also cannot compete except for the biggest killers. E.g, ending malaria or halving illiteracy each would cause an amount of good comparable to range voting, but would probably be more difficult to accomplish.
(Other simple inventions that can powerfully improve the lot of humanity. Comparison with Sakharov and the limited test-ban treaty. Other reform-importance estimates.)