First, I’m talking very much about the London and the South East as that‘s the market I know. But the effects are heading north by the way.

In the depths of the early 1990s property crash transaction volumes for first-time buyers with a mortgage were twice what they were in the 2008/9 crash.

The difference lies partly in the extent of the Government and Bank of England’s intervention in 2008/9. Emergency interest rates and QE helped avoid the scale of repossessions seen in the 1990s.

But buy-to-let also helped support the market post-2008/9. If you wanted to move but a first-time buyer couldn’t afford your house you didn’t have to sell it, unlike in the 1990s. You could rent it out and buy/move somewhere else.

However, that created more demand for BTL due to its perceived safety and superior returns, which is where things started to go wrong.

You say “BTL grows to fill the demand from people who can afford to pay to live somewhere, but can’t find a deposit”. That’s true, but at some point BTL’s effect on house prices is such that it creates that demand.