How is the current government of Argentina
different from the government in the 1900s?
http://en.wikipedia.org/wiki/Argentina
See Modern History section, and contemporary history. It is hard to separate "government" from economics, trade, and growth. I think the short answer is that in 1900, the government was well run, and the population cohesive to think in econmic growth. Current Government is still struggling with the decisiveness left by Peron, which left the country with bitter factions.