[vanderZwan]

First, I don't understand what you are trying to argue, as that "engine" works by redistributing their wealth.

Second, John Kay's arguments are not contradicting (or even discussing) the main premise of Bill Gates' letter - which is to convince people aid is effective, but one specific argument made within it regarding wealth and the global economy:

> I was surprised and disappointed that the data you chose to support your case referred not to the distribution of average incomes across states – the subject of your letter – but to the distribution of household incomes across the world. These are very different things.

If I was an economist, I would also point out that mixing up the data like is disingenuous and probably damaging to the overall argument, even if to lay-people like you and me it makes little difference.

Finally, as far as I can see the author of this article and Gates want the same thing: to help the poorest on the planet. The difference is that Gates focuses on what has worked and what his vision is of what happens when things go right. Kay on the other hand focuses on what has gone wrong and is still going wrong and why, and thus is deserving of being paid attention to by people with the power and intent to change things (like Bill Gates for example). This is constructive criticism.