Is the typical specification of the Euler equation for investment employed in DSGE models consistent with aggregate macro data? The answer is yes using state-of-the-art econometric methods that are robust to weak instruments and exploit information in possible structural changes. Unfortunately, however, there is very little information about the values of the parameters in aggregate data because investment is unresponsive to changes in capital utilization and the real interest rate. Bayesian estimation using fully-specified DSGE models is more accurate due to both informative priors and cross-equation restrictions.