It's a question barely worth asking, I'd have thought, but Peter Singer asks it nonetheless - Why do people give generously to earthquake victims, but not to prevent the much larger number of deaths caused by poverty? The assumption, I suppose, is that people are acting irrationally, but a professional philosopher is able to see more clearly and so point out the shoddy thinking:
Perhaps people respond more generously to the victims of natural disasters than they do to those in extreme poverty because, after a natural disaster, we tend not to blame the victims. We seem to accept that to be struck by an earthquake, a tidal wave, or a hurricane is just bad luck (unless, as the American evangelist Pat Robertson suggested after the Haitian earthquake, your ancestors made a pact with the devil in order to free themselves from colonial rule).
Still, many people profess to believe that poverty is the result of not working hard enough, or of having too many children. But the circumstances that produce extreme poverty are not, except in rare cases, under the control of such poor people. They may be, to some extent, under the control of governments, and undoubtedly bad government is a major contributor to poverty. But then, bad government can also contribute to the toll exacted by a natural disaster.
It all comes down to assuming the worst about the donating public: in general an assumption that goes down very well with CiF commenters. They - the public - apparently think that the victims of a tragedy are deserving, but the poor are not.
Alternatively, they could be acting sensibly. The eradication, or at least alleviation, of poverty is and has been one of the major driving factors in politics, on the national and international level, for years and years. It ain't easy. It ain't easy at all. Giving to charity, which is what Singer seems to assume will solve the problem, has been tried, endlessly, tirelessly, on and on and on and on. It can do wonders in the short term - as, for instance, in the case of a natural disaster - but is being questioned more and more as a long-term answer. In fact it's probably by now more part of the problem than part of the solution. It doesn't seem to work.
People are still remarkably generous in their donation to charities. If Peter Singer can present a foolproof method of saving a million lives by spending the odd million dollars then he should present his case to the UN and take his place as one of humanity's greatest benefactors - or join the charity marketplace where competing claims are made by competing charities each busy assuring us that their particular cause is the most deserving.
So, the answer to the question is: people, in so far as they do give more generously to earthquake victims than they do to the world's poor, do so because they believe, quite rightly, that their money is more urgently needed and will do more good in the former rather than the latter case. Because people, unlike some philosophers, can generally see what's under their nose.