I think it'd be fun to list all the reasons we were told borrowing was a bad idea in 2012 and see how many are legitimately changed by today's circumstances. Point 1: NO ONE used the actual cost of borrowing in 2012 - it was super cheap! Sub 2.0%! So here goes... 1/
"Government spending crowds out the private sector" - well if that was true when unemployment was 7% it's more likely to be the case now it's half that
"It's really hard to find good uses for government investment" - well in 2012 we'd recently scrapped a bunch of projects, which might have been restored. Maybe they were rubbish. But it's no easier now
"The bond markets will pick on the UK" - this seems more likely to be the case when we're doing something as idiosyncratic as Brexit, tbh
"We've got a long way to go to lower the fiscal deficit" - true in 2013, though I'd be surprised if the two year out forecast of the PSNB is that much better now. And in 2014 the then Chancellor started claiming we needed a total fiscal surplus...
"Fiscal policy doesn't have any effect on demand growth, that's what monetary policy is for" - I have more sympathy with this than most, but rates were stuck at the lower bound then, until recently they were higher in 2020.
"We have to keep cutting the deficit because there's a magic debt-GDP level at which the markets and economy puke (90%)" -eerr, obviously wrong then, but it would apply even more now
Conclusion, too obvious to spell out really: this is mostly an opportunistic change of governing ideology. Maybe a welcome one! But getting fiscal religion just as we hit maximum capacity and appear to suffer a couple of supply hits - it's interesting timing
