Re. the 4th candidate for the Filter, what we need is a single planetary economy that is not divided by national interests. We can achieve that with a single planetary supply of money that would enter the planetary economy in the form of an income paid to individuals. Sovereign nation-states would continue to exist, but the economy would be thoroughly globalized from the bottom up. I have worked out the details at the national level, but this paradigm could be scaled to the global level with relative ease.