* Has the time of the United States as the world's leading economic power come to an end?
I do not think so. Her greatest advantages are continual innovation, attractiveness for immigrants, and the ideology of pragmatism. China and India are sleeping giants that were snoring for some time; they have awakened now. But they cannot match the United States in these advantages.
* In 2020, will China be the world's economic superpower, or will it have collapsed just like Japan and other former would-be economic powers of the world?
Many thought that the 21st century would be Japan's but I always thought it would still be, like the 20th century, that of America's. Now, many think it will be China's. But they are equally mistaken. China's problems arise from the crippling effects of its lack of democracy and the absence to date of the supporting institutions such as a free press, opposition parties, an independent judiciary and NGOs (i.e. civil society). The lack of these institutions of a "liberal" democracy means that environmental damage has been immense, and political and economic aspirations have no outlet other than social unrest. Equally, her export-oriented model will increasingly run into human rights opposition abroad, whereas safety problems (which cannot be handled just by passing laws and enforcing punishments) will multiply.