From an article bySerena Ng and Jonathan H. Wright (gated)

There has been a secular increase in the share of services in consumption from an average of 50 percent before 1983 to 65 percent after 2007, at the expense of nondurables (from 35 percent to 22 percent). Labor share in the nonfarm sector has fallen, as has the share of manufacturing employment. The civilian labor force participation rate stands at 63.5 percent in 2013, much below the peak of 67.2 percent in 1999. This is in spite of the female participation rate rising from under 35 percent in 1945 to over 60 percent in 2001, as the male participation rate has been falling since 1945. The economy has experienced increase openness; international trade and financial linkages with the rest of the world have strengthened, with the volume of imports plus exports rising from 12 percent of GDP before 183 to 27 percent post-2007. Meanwhile, not only have households’ and firms’ indebtedness increased, so has foreign indebtedness. For example, the household debt-to-asset ratio rose from under 0.75 in the 1950s to over 1.5 in 2000 and has since increased further. Net external assets relative to GDP have also risen from 0.82 in the 1970s to 2.4 when the sample is extended to 2007.

Keep in mind that the conceit of macroeconometrics is that each quarter is an independent observation, and that by controlling for a few variables one can make, say, 1982 Q1, equivalent to 2009 Q3, except for key policy drivers. If you cannot buy that (and of course you cannot), then I believe that you have reasons to be skeptical of any purported estimates of multipliers.