How concentrated has wealth become in the globalized modern world? Here’s one answer: Just eight of the richest people on earth own as much combined wealth as half the human race. That’s a notable change from last year, when it was reckoned to take 62 of the superrich to match the assets of the 3.6 billion people in the poorer half of mankind. The charity Oxfam does the math each year and publishes its results just in time for the World Economic Forum in Davos, Switzerland, where many of the...