According to the Economist:
…How might these problems be fixed? One possibility is simply to raise the inflation target to, say, 4%. Credibly enacted, that ought to alleviate the risk of impotence. If investors and consumers believe inflation will reach 4%, nominal interest rates should eventually rise to 5% or so even if real rates stay low. But rich-world central banks have undershot their targets for so long they may struggle to persuade the public to expect higher inflation. And a higher target would still leave central banks with a dilemma when economic growth and inflation diverge. Neither would it make up for big misses.
A more radical option is to move away from targeting inflation altogether. Many economists (and this newspaper) see advantages in targeting the level of nominal GDP, the total amount of spending in the economy before adjusting for inflation. A nominal-GDP target would allow for temporary variations in inflation. Downturns would be tempered by an expectation of protracted stimulus later on to make up lost ground. In better times, a rise in real GDP would provide the lion’s share of the required nominal-GDP growth and inflation could drift lower.