Critical Finance Review > Vol 7 > Issue

On Long-Run Stock Returns After Corporate Events

James W. Kolari, Texas A&M University, , USA, Seppo Pynnonen, University of Vaasa, Finland, Ahmet M. Tuncez, Adrian College, USA,
Suggested Citation
James W. Kolari, Seppo Pynnonen and Ahmet M. Tuncez (2018), "On Long-Run Stock Returns After Corporate Events", Critical Finance Review: Vol. 7: No. .

Forthcoming: 01 Oct 2018
© 2018 J. W. Kolari, S. Pynnonen and A. M. Tuncez
Abnormal returnLong-run event studyCharacteristic normalizationMerger and acquisitionIPOSEODividend initiation

Article Help


Download article
In this article:
1. Characteristic Normalization
2. Data and Methodology
3. Empirical Results
4. Conclusion


Bessembinder and Zhang (2013) show that long-run abnormal returns after major corporate events detected by the buy-and-hold abnormal return method using size and book-to-market matched control stocks can be explained by differences between event and control stocks’ unsystematic and systematic characteristics. We find that their results are mainly driven by the normalization of firm characteristics, which was intended to make estimated regression coefficients comparable. Unfortunately, their normalization procedure implies incremental nonlinearity and randomizes regression relations. These effects influence the slope coefficients, potentially bias alpha, and materially inflate its standard error, which causes even economically large alpha estimates to be insignificant. Revisiting their regression analyses shows that, even though the event firms and their controls differ in terms of various characteristics, these differences do not generally eliminate abnormal returns as measured by alphas.