Also, while there are many successful former British colonies, the average GDP for former British colonies is lower than the worldwide average, so it's more complicated than did the Brits colonize them. I'm sure it would be impossible to dive into this without a lot of time, and the willingness to take on politics--neither of which are available to me right now, but the difference in modern GDP between countries like Egypt and Jordan on the one hand, and Qatar and Kuwait on the other can probably be explained by oil wealth. But what about Israel, which has a GDP more like the latter, without the oil wealth? Similarly, the differences between Trinidad and Tobago, the Bahamas, and Barbados on the one hand, and Jamaica, Belize, and Guyana (or just a comparison of all of the former British colonies in the Caribbean) would be pretty interesting to see what went right and what went wrong that there is such a difference between them.