Courtesy of Stumbling and Mumbling we find that:
"But the truth - of course - is that people do, at the margin, respond to incentives. If you raise the cost of having children, people will have fewer of them.
For example, this study of the introduction of working tax credits - which increased work incentives for single parents - found that the move "led to a significant reduction in single mothers’ subsequent fertility." This paper finds that:"Financial incentives play a notable role in determining fertility decisions in France...Adding to the existing tax-benefit system a child subsidy of 150 euros per month...would raise total fertility by about 0.3 points."And there's also evidence here (pdf) from Israel."
And because Flight is now proved so obviously right, he has to apologise?