Looking at http://en.wikipedia.org/wiki/Globalization a world government seems highly unpopular idea among many people. Looking at the relevant history suggests that basic things—like a single currency—are still some distance away.
Also, if one forms, it is unlikely to be all-powerful for a considerable period of time—a fair quantity of the resulting dynamics will arise from selection effects and self-organization dynamics—rather than its wishes.
Looking at http://en.wikipedia.org/wiki/Globalization a world government seems highly unpopular idea among many people. Looking at the relevant history suggests that basic things—like a single currency—are still some distance away.
Also, if one forms, it is unlikely to be all-powerful for a considerable period of time—a fair quantity of the resulting dynamics will arise from selection effects and self-organization dynamics—rather than its wishes.