There are too many sweeping statements in public discourse – and one of the broadest is that ‘foreign aid doesn’t work.’

The most basic thing to understand about aid is just how many different kinds there are. If one is saying that some of these don’t work, then that is a respectable argument (though essentially one for reform not abolition). If, however, the argument really is meant to apply across the board, then to make a credible case one must either have a comprehensive knowledge of aid programmes around the world – or, more likely, evidence that powerful underlying factors are bound to frustrate all aid efforts no matter how well intentioned.

In their Gates Foundation annual letter, Bill and Melinda Gates identify and rebut three of these supposed impediments.

Firstly, there’s the notion that there’s simply no hope for certain parts of the world – Africa being the most obvious example:

“Income per person has in fact risen in sub-Saharan Africa [in the last fifty years], and quite a bit in a few countries. After plummeting during the debt crisis of the 1980s, it has climbed by two thirds since 1998, to nearly $2,200 from just over $1,300… Seven of the 10 fastest-growing economies of the past half-decade are in Africa.

“Africa has also made big strides in health and education. Since 1960, the life span for women in sub-Saharan Africa has gone up from 41 to 57 years, despite the HIV epidemic… The percentage of children in school has gone from the low 40s to over 75 percent since 1970.”

Secondly, there’s the argument that aid spending disappears into a black hole of waste and corruption. For instance, there was a scandal last year in Cambodia in which local officials “were caught taking six-figure kickbacks” from contractors working for the Global Fund to Fight AIDS, Tuberculosis and Malaria. Bill Gates acknowledges the problem, but tells us to put it into perspective:

“There is a double standard at work here. I’ve heard people calling on the government to shut down some aid program if one dollar of corruption is found. On the other hand, four of the past seven governors of Illinois have gone to prison for corruption, and to my knowledge no one has demanded that Illinois schools be shut down or its highways closed.

“Melinda and I would not be supporting The Global Fund, or any other program, if the money were being misused in a large-scale way. Malaria deaths have dropped 80 percent in Cambodia since The Global Fund started working there in 2003.”

Those who call for ‘trade not aid’ (as if the two were mutually incompatible) should note that a great deal of the former also gets mired in corruption. Does that mean we should stop doing business with the developing world?

Thirdly, we have the modern-day Multhusians who insist that reducing child mortality will only result in overpopulation and all the problems that come with it. Therefore, they say, there’s no point in helping poor countries until they get their birthrates under control. It’s a commonly made argument, but as Melinda Gates explains it reverses the cause and effect:

“When children survive in greater numbers, parents decide to have smaller families. Consider Thailand. Around 1960, child mortality started going down… Today, child mortality in Thailand is almost as low as it is in the United States, and Thai women have an average of 1.6 children.”

Thailand is no exception; in one country after another, the figures show that birthrates fall when child mortality falls, not the other way round:

“Given all the evidence, my view of a sustainable future is much more optimistic than the Malthusians’ view. The planet does not thrive when the sickest are allowed to die off, but rather when they are able to improve their lives. Human beings are not machines. We don’t reproduce mindlessly. We make decisions based on the circumstances we face…

“When children are well-nourished, fully vaccinated, and treated for common illnesses like diarrhea, malaria, and pneumonia, the future gets a lot more predictable. Parents start making decisions based on the reasonable expectation that their children will live.”

Of course, there are still many examples of poorly designed and implemented aid programmes. Given the accumulated experience of what does and doesn’t work, there is increasingly little excuse for these failures.

But, equally, the excuses for not giving aid are also running out.