The absence of pass-through does not reflect a change in the fundamental effectiveness of monetary policy so much as the offsetting effect of other financial shocks that were occurring at the same time the Fed was easing.
One way of quantifying the degree of pass-through is to compute a financial conditions index that combines the effects of all the transmission channels into a single number. Goldman Sachs and Macroeconomic Advisers have developed differing methodologies for computing such an index. Basically, they weight changes in various financial conditions by their relative importance as determinants of private spending.