The days of low inflation may be coming to an end, if a new analysis from the Federal Reserve is right.

While high unemployment has kept inflation low for the past few years, according to researchers at the New York Fed, short-term unemployment has now returned to a normal level. And it's short-term unemployment, not still-high long-term unemployment, that matters for wage growth, write economists M. Henry Linder, Richard Peach and Robert Rich.

the above chart shows that short-duration unemployment has returned to a level consistent with a healthy economy. Total unemployment remains high — at 6.6 percent in January — because of the unusually large number of Americans who have been out of work for 27 weeks or longer. The long-term unemployed made up over a third of all those out of work in January.

But it's the short-term unemployment rate that drives wage growth, according to the New York Fed's analysis.

The researchers went back through the data and found that a model of wage growth that uses the short-term unemployment rate as a measure of slack, rather than the overall unemployment rate, fits the data for the past few years better:

This model might explain why the U.S. avoided outright deflation even as the unemployment rate spiked to 10 percent following the financial crisis, and also why inflation has remained low throughout 2013 as unemployment has declined.

The New York Fed's model is based on research by Northwestern professor Robert Gordon, who suggested that the“U.S. economy may have become more like Europe,” with permanently higher unemployment that cannot be ameliorated by monetary or fiscal policy.

The bottom line: The U.S. may be poised for wage growth, and subsequently inflation, in the months ahead.