"Even what may appear as a benign intervention on the surface can have
damning consequences. Say there is a mosquito-net maker in small-town
Africa. Say he employs 10 people who together manufacture 500 nets a
week. Typically, these 10 employees support upward of 15 relatives
each. A Western government-inspired program generously supplies the
affected region with 100,000 free mosquito nets. This promptly puts the
mosquito net manufacturer out of business, and now his 10 employees can
no longer support their 150 dependents. In a couple of years, most of
the donated nets will be torn and useless, but now there is no mosquito
net maker to go to. They'll have to get more aid." Wall Street Journal