The prolonged slowdown in crude oil prices has hit oil-producing countries hard, and the rich Persian Gulf kingdoms are no exception, prompting them to try diversifying their economies. Dubai, the most populous of the seven emirates in the United Arab Emirates, is arguably the most diversified economy in the region, and yet, in a telling sign of the times, it has announced a new tax on all passengers, even transiting ones, that travel through its two airports, a move designed to buffer up the emirate’s coffers.