My guess is that we're reaching the beginning of the end of 400 years I say 400 years because it's the end of the Ottoman Empire of the hegemony of Western power, Western institutions and Western values.

My guess is, for what it's worth, is that the United States will remain the most powerful nation on earth for the next 10 years, 15, but the context in which she holds her power has now radically altered it has radically changed.

My guess is that there's nothing quite that specific in our evolutionary past. But rather, if you're looking for an evolutionary explanation, you might say that most organisms are neo phobic that is, they're a little scared of stuff that's new and different.

Alleviating poverty is more guesswork than science, and lack of data on aid's impact raises questions about how to provide it. But Clark Medal winner Esther Duflo says it's possible to know which development efforts help and which hurt by testing solutions with randomized trials.