Should we Target NGDP?

In my last post, The UK and Europe, the Way Forward, I wrote that 

"The Bank of England should make clear that a catastrophic drop in the financial markets will not be permitted. I recommend a statement that the Bank will, if necessary, buy shares in an  exchange traded fund to support the value of the FTSE and that it will pay for those shares by selling short-term treasury securities. As I argued here, if necessary, the Treasury should support that action by providing the Bank with the authority to borrow on its behalf."

Thomas Hutcheson, commenting on my blog writes,

"This is fine so far as it goes, but we should deal as well with the policy response of the ECB and the Fed, as well. Whatever long term damage may occur from slightly less free trade (including investment to trade) cannot be prevented by central banks, but they can prevent the damage that comes from uncertainty about the future course of NGDP. It is expectations about that they should seek to stabilize."

Here is my response. 

I am in broad agreement with the proposal to stabilize expectations of future NGDP growth and, in the simple models that guide my thinking, stabilizing asset price growth and stabilizing expectations of NGDP growth amount to the same thing. The question is: how to achieve that goal?

If central banks simply substitute NGDP targeting for inflation targeting, and if they continue to try to achieve their objective by adjusting short term interest rates, not much will have been achieved. Scott Sumner has proposed instead, that central banks should trade NGDP futures. Robert Shiller goes further and advocates that national governments finance their borrowing requirements by issuing equity-like instruments that pay a trillionth of GDP: Shiller calls these 'trills'. I wholeheartedly endorse both of these proposals. Creating a market for nominal GDP futures, and actively trading trills for Tbills would have much the same effect as stabilizing asset price growth. 

I differ from Scott in one important respect. Whereas Scott sees NGDP targeting as a substitute for inflation targeting, for me, it is a complement. Central banks should set interest rates to target inflation, and they should set the growth rate of some other object, be it asset prices, NGDP futures, or the price path for trills, to target the unemployment rate.

You can read more about these ideas in my new book, Prosperity for All.