In the London Times:

Europe needs more babies – the average continental family has a mere 1.37 children. Cutting back non-EU immigration to limit pressure on housing stock would help. So would state cash handouts. In Portugal, where the birthrate has fallen to 1.7 children per couple, the Government has considered giving tax breaks to people who have more than two children and levying higher taxes on those who have fewer. Germany is similarly concerned – it could lose the equivalent of the population of the former East Germany within 50 years. Russia’s population is contracting at the rate of three quarters of a million a year: the resourceful Mr Putin is paying mothers to have a second child.
The last thing we should be doing is bullying people to breed less. The population controllers have to be put back in their box. You know, Augustus Caesar had a tax on Roman bachelors. With due allowances for gay men and professional celibates, there’s lots to be said for the idea.