How to spot when a policy is not working

Imagine your city had a housing problem. Lots and lots of people wanted to buy houses there, live there. And there weren't all that many houses for them to do so in. You had some policy ideas about this and brought them into action. At which point this happens:

Housing starts in Vancouver have fallen to their lowest level in more than five years while home sales plunged 38.8% compared with October of last year.

Your problem is a shortage of supply of housing. Your actions have curtailed the supply of housing. Yep, that's a failure alright.

So, what did they actually do?

Mounting public anger and a chorus of concern emanating from the country’s banks forced a turnaround in recent months. In August, the province of British Columbia instituted a 15% tax on all home buyers in metro Vancouver who are not Canadian citizens or permanent residents. Soon after, the federal government said it would close a tax loophole believed to be used by some speculators.

The city of Vancouver has proposed its own measures in recent months, from a 1% tax on vacant homes starting next year – after an attempt to do so last year was stymied by the provincial government – and a crackdown on short-term rentals, such as those done through Airbnb.

Those aren't the same as what has been proposed over here but there's a definite echo there, isn't there? Which gives us an inkling about how well the policies proposed here would work.

And of course the actual solution to a shortage of supply is to increase supply. Make it easier for people to build more houses - here in the UK that means blowing up the Town and Country Planning Act of course.