Krugman has gone over the edge, now proclaiming that virtually any kind of spending, no matter how productive is beneficial.
This puts us in a world of topsy-turvy, in which many of the usual rules of economics cease to hold. Thrift leads to lower investment; wage cuts reduce employment; even higher productivity can be a bad thing. And the broken windows fallacy ceases to be a fallacy: something that forces firms to replace capital, even if that something seemingly makes them poorer, can stimulate spending and raise employment. Indeed, in the absence of effective policy, that’s how recovery eventually happens: as Keynes put it, a slump goes on until “the shortage of capital through use, decay and obsolescence” gets firms spending again to replace their plant and equipment.
And now you can see why tighter ozone regulation would actually have created jobs: it would have forced firms to spend on upgrading or replacing equipment, helping to boost demand. Yes, it would have cost money — but that’s the point! And with corporations sitting on lots of idle cash, the money spent would not, to any significant extent, come at the expense of other investment.
So why not force corporations to build ice sculptures in their cafeterias or something? At least that would look nice.