In his latest column for CBS Moneywatch, Mark Thoma asks How long will it be until the Fed raises interest rates?  And he shares some helpful recent analysis from Glenn Rudebusch, senior vice president and associate director of research at the Federal Reserve Bank of San Francisco.  Rudebusch has a collection of graphs that hit on seemingly all of the key variables when it comes to monetary policy decisions. 

From the positive trends...

...to the not so positive.

Rudebusch argues that the unemployment rate is key, and that the slow rate of recovery for jobs trumps overall economic recovery when it comes to any move on the target interest rates:

Given the extended nature of the expected recovery to levels of unemployment and inflation consistent with the Fed's mandate for full employment and price stability, the policy rule also suggests little need to raise the funds rate target anytime soon. Of course, this projection of future policy will change as economic forecasts are revised. Such conditionality is consistent with the FOMC's forward-looking policy guidance from its January 26 meeting, that "economic conditions, including low rates of resource utilization, subdued inflation trends, and stable inflation expectations, are likely to warrant exceptionally low levels for the federal funds rate for an extended period." In the simple rule, the length of the "extended period" depends on the expected paths for unemployment and core inflation. Therefore, the downward revision over the past few months to the projected path of the unemployment rate translates into a higher path for the funds rate and an earlier liftoff from a zero funds rate. However, according to the simple policy rule of thumb, the positive unemployment news since last October appears to have shortened the duration of the "extended period" of near-zero interest rates by only about three months. Substantial monetary policy accommodation appears warranted for some time.

Read all of Rudebusch's analysis here.