NGDP targeting is roughly the same as inflation targeting

David Glasner has a great new post up about the discussion I referenced in my last couple of posts (here and here) about whether the liquidity trap will ever end. He does give a nod to NGDP level targeting at the end:

And maybe there is no better argument for nominal GDP level targeting than that it offers a practical and civilly reverent way of allowing monetary policy to be effective at the zero lower bound.

That might be true, but if the information equilibrium model is correct, then NGDP targeting is no better than inflation targeting unless you are pursuing a controlled hyperinflation.
I showed a simple proof in the information equilibrium model that there always exists a level of the monetary base where monetary policy becomes ineffective as long as the central bank targets some market variable.
I also showed here that NGDP targeting is actually the other side of the inflation targeting coin -- one targets an ideal NGDP, the other targets an observed NGDP and only one can be targeted because we don't have perfect information about the future. Either both NGDP (level or growth rate) or inflation targeting (including price level) work or both don't work depending on whether the unknown future distribution of market variables is stable or not (but see update below).


Update 6/5/2015

Additionally, with the maximum inflation rate and the NGDP growth path slowing over time, no constant inflation target or NGDP growth rate target (or price levels or NGDP levels that are above these paths) will be sustainable over the long run.