Policy analysis is like a lot of other project work. It can be good, it can be fast, and it can be cheap – but it cannot be all three. You have to pick two. And that is a problem when an incoming government wants to make a lot of policy changes on a hundred-day clock.

Policies are meant to be accompanied by impartial and rigorous assessments from the Ministries, or from Treasury.

That advice helps Parliament consider its options and helps inform voters. If the Ministry’s advice is that a policy will not solve the problem it is meant to solve, or that it will have a lot of unintended negative consequences, journalists or the Opposition will make sure that voters find out.

But that process gets short-circuited when Cabinet is in a hurry. The Impact Statements accompanying 100-day plan policies have explicit caveats written into them about the constraints under which they were produced. And a lot of them just are not up to the expected standard.

Consider the government’s proposed ban on foreign buyers of residential property.

The New Zealand Initiative’s submission identified several problems in Treasury’s assessment of costs and benefits. The New Zealand Institute for Economic Research (NZIER)’s submission was even more scathing than ours, describing parts of Treasury’s work as a flag of surrender.

Other submissions even showed the legislation will also hit lines and telecom companies needing to buy residential land to put up things like cell towers.

Even worse, the short submission period for 100-day legislation fell over the Christmas holidays. There will be plenty of other problems that will only be identified when we slam into them.

Government sometimes has to legislate in haste. When that haste is at the cost of proper assessment, the public deserves better protection through more rigorous post-implementation policy reviews.

The Ministries do not have a great record in following through with these reviews, but there may be a solution.

Sunset clauses put a time limit on policies. A sunsetted policy simply expires unless Parliament has intervened before the clause’s deadline. Imagine if policies like the ban on foreign buyers would automatically expire in two years absent a successful post-implementation review and subsequent reauthorising legislation removing the sunset clause.

If we legislate in haste, we may repent at leisure. Would it not be better to take that leisure-time to re-evaluate instead?