NZ has the dubious distinction of having one of the highest rates of 'severe unaffordability' of houses in the world...
This is basically comparing house prices and income. It is ludicrous here - houses are so, so expensive. I'm in a pricy suburb admittedly, but the starting price for 3-bed homes with a bit of lawn outside (i.e. the sort of home Kiwis should be able to take for granted) is around the $800,000.00 mark (c £400,000.00). You're looking at over a million bucks for more of a 'forever home'.
I've recently returned home from the UK and we're renting at the moment. The rental market from the renter's perspective is incredibly competitive. There's just nothing out there - it is dog-eat-dog trying to secure somewhere, the demand is so high.
I've been away from a long time - since my early 20s and am now late 30s so it's difficult for me to make comparisons to what it was like before I left as I just wasn't particularly interested or aware of the situation, but it does seem as if very few people do the buy-to-let thing, probably because house prices are so ludicrously high that it's enough of a struggle to get a decent family-sized home as it is, let alone buy a second home - and especially when you take the very high interest rates into account as well.
The thing is, everything is expensive here - I just thought this was indicative of the overall picture, but the results of this affordability surgery have just been released and it seems this is actually a real issue.