As the author of a book on logical fallacies, I am often asked what is the most common fallacy committed by politician and political writers. The answer, perhaps disappointingly, is the “argumentum ad hominem (abusive),” the fallacy of thinking that because you have attacked the arguer, you have also attacked his or her argument. Of course it is untrue, as is fairly obvious. If I were instead asked what is the most important fallacy committed by political people, the answer would be different. It is probably the “zero sum game fallacy,” the false supposition that something is in fixed supply when it is not.
The most obvious instance is when people falsely suppose that if poor people are to receive more money, it must come from richer people. No, the wealth pie it not fixed. Poor people can receive more money by having more wealth created in the economy, so their access to it increases along with that of other people. It can come through growth, rather than redistribution.
Nowhere is this more true than in international development. Poor countries do not become rich by having wealth redistributed to them from richer countries through development aid. They become rich by creating wealth through trade and exchange. No countries had ever done it through aid, and no country has ever done it without trade.
Rich countries like the UK did not become rich by taking it from other countries. It was not there. The wealth had to be created. The wealth of the world 250 years ago was a tiny fraction of what it is today. It has been created by specialization and trade. The wealth was created in our Industrial Revolution, and many other countries followed the same path.
An important lesson is that those who want the poor to become richer should be promoting economic growth rather than concerning themselves overmuch with redistribution. They should be trying to grow the pie, not to reapportion it.