Two-pass cross-sectional regression (TPCSR) is frequently used in estimating factor risk premia. Recent papers argue that the common practice of grouping assets into portfolios to reduce the errors-in-variables (EIV) problem leads to loss of efficiency and masks potential deviations from asset pricing models. One solution that allows the use of individual assets while overcoming the EIV problem is iterated TPCSR (ITPCSR). ITPCSR converges to a fixed point regardless of the initial factors chosen. ITPCSR is intimately linked to the asymptotic principal components (APC) method of estimating factors since the ITPCSR estimates are the APC estimates, up to a rotation.

We use short interest as an investor-based measure of over- or undervaluation that distinguishes between the misvaluation and Q-theories of mergers. Using this measure, we find that misvaluation is a strong determinant of merger decision-making. Firms in the top quintile of short interest are 54% more likely to engage in stock acquisitions and 22% less likely to engage in cash acquisitions. Stock (but not cash) acquirers have higher short interest than their targets. Overall, our results suggest that the previously documented underperformance of stock acquirers and the overperformance of cash acquirers can be explained by misvaluation, as captured by short interest.