4% wouldn't be bad. People tend to focus on prices, but look over the fact that it moves stagnant money in bonds. Companies have to shift to looking for more revenue, rather focusing just on growth (mergers) and keeping huge piles of cash on hand as they are now; less inflation eat it away.
It also should be good for wages in a competitive job market, although realistically I think employment pricing is far too captured by various industries to push up wages much.
Two of the biggest issues with the economy are too big to fail companies dictating supply/demand, and the lack of liquidity; money pooling in the hands of the 0.01% and fortune 500 behemouths. Wealth isn't created from stashing cash in low interest sovereign bonds, in nations that aren't using it to spend on investments in education or infrastructure.
Inflation overwhelmingly impacts the poor more than the rich, and makes the distribution of wealth even more unequal.
http://www.sciencedirect.com/science/article/pii/S0165188906000157
The effects of a permanent change in inflation on the distribution of wealth are analyzed in a general equilibrium OLG model that is calibrated with regard to the characteristics of the US economy. Poor agents accumulate savings predominantly in the form of money, while rich agents participate in the stock market and accumulate equity. Higher inflation results in higher nominal interest rates and a higher real tax burden on interest income. Surprisingly, an increase in inflation results in a lower stock market participation rate; in addition, savings decrease and the distribution of wealth becomes even more unequal.
I say stick to 2%.