There was an intriguing short letter in the Financial Times this morning, urging that more attention be paid to the problem of a low birth rate and the adverse demography of an ageing society.  The writer evidently believes the welfare system should be encouraging people to have more children, rather than penalising them for large families. He cites a 1947 book, [amazon_link id=”B00195GT00″ target=”_blank” ]The Population of Britain[/amazon_link] by Eva Hubback.

[amazon_image id=”B00195GT00″ link=”true” target=”_blank” size=”medium” ]The Population of Great Britain[/amazon_image]

Looking her up, Wikpipedia tells me Eva Hubback was a suffragist, head of economics at Newnham and Girton during the First World War, and advocate of birth control and eugenics. However, her book clearly advocates the national benefits of population growth. This is an intriguing combination of beliefs, very much of its time.

It has long seemed to me that economics doesn’t pay enough attention to demography. Obviously, people studying pensions and the fiscal implications do put the ageing trend at centre stage, and relative demographic trends crop up in work on international migration. But demography is surely fundamental for growth as well. One question is whether an older (on average) population will be as productive and innovative as a younger one. And if so, what does this imply for, say, predictions of Chinese economic power?

Another is simply the numbers game. Endogenous growth models imply that the growth rate is increasing in population, at an accelerating rate because of their increasing returns feature. Ideas live in people’s heads, and the combinatorial arithmetic makes more people generate many more ideas. This is something modern economists (although clearly not Eva Hubback) seem to gloss over with mild embarrassment.

The best book I’ve read including demography, although in a broader context than economic growth, was Emmanuel Todd’s 2001 [amazon_link id=”1845290585″ target=”_blank” ]After the Empire[/amazon_link]. He was looking ahead to the multipolar world. But I’d be interested to hear other recommendations.

[amazon_image id=”1845290585″ link=”true” target=”_blank” size=”medium” ]After the Empire[/amazon_image]