All over Europe right now, there is a terror alert; there are even fears of a 'Mumbai-style' urban jihadist attack of the sorts we saw in 2008. Over in the US, the controversy surrounding plans to build a mosque near the site of the 9/11 terror attacks in New York has sharpened focus on a larger debate: should the US fear Islam? Others contend, more controversially, that Islam will "conquer all other religions" - and "Allah's prediction" will soon come to pass!

Some of these fears that Islam will "conquer the world" arise, in part, from perceptions about dramatic changes in religious demographics, particularly in Europe and America. There are those who argue that a "demographic time bomb" is transforming Europe. It manifests itself in fears that London is becoming Londonistan - that the spread of Islamism is creating a terror state in Britain - and that radical Islam is destroying Europe from within. It also finds expressioin in a cultural backlash that has seen France ban the hijab in public places, and a controversy in Switzerland over the construction of minarets.

Recently in Hong Kong, I sat down with demographer and economist Dr Richard Hokenson to explore this and other themes. I asked him whether fears of an "Islamisation" of Europe and other parts of the world were justified by changes in religious demographics.

His response:

"The fear about the 'Muslimisation' of Europe is based on false premises... It's the world's biggest myth. It's in the Muslim world that birth rates are falling the fastest, including in Uzbekistan, Saudi Arabia, the Emirates, Yemen and Iraq; in Iran it's already below replacement level. And even in Afghanistan and Pakistan, it's falling at a slower rate.When women from high birth rate countries move to low birth rate countries like those in Europe, they adopt the local standard."

I also discussed other demographics-related topics relating to India and China. Of India, it's often said that it's in a "demographic sweet spot", but Hokenson argues that for India to harvest this dividend, it has to get a few things in place - such as improve education, and enhance agricultural productivity so that surplus labour can move to the cities.

And as for China, which faces an ageing population and a labour force that will begin to decline in size in a few years, Hokenson says - again taking a contrarian line - that reversing or reforming the controversial one-child policy (as some provinces are talking of doing by 2030 - won't help. That's because fertility rates in China had already collapsed when the one-child policy was implemented in 1979.

In the interview, Hokenson also debunks other demographics-related myths: that it isn't a population explosion we should be worried about at a global level, but a population implosion.

You can read the interview as it appeared in the September 25 print edition of DNA here - but owing to space constraints, the full interview couldn't be accommodated, so I've uploaded it here. Am sharing it in the hope you'll learn as much from it as I did.