The Weighting Bias

Publication Date

4-3-2025

Abstract

I develop a framework to reconcile the conflicting results on long-run IPO performance based on the matching firm approach and the calendar time portfolio approach. The approaches differ in their weighting schemes: the former gives equal weight to each firm and the latter to each period. While IPOs exhibit lower buy-and-hold returns than their matched counterparts, portfolios of IPO and matched firms generate alphas of similar magnitudes. This discrepancy stems from a weighting bias inherent in the matching firm approach, driven by non-random IPO firm survival. My findings underscore the crucial role of the weighting bias when evaluating long-run performance.

Document Type

Article

Keywords

weighting bias, long-run firm performance

Disciplines

Finance

DOI

10.2139/ssrn.5205685

Source

SMU Cox: Finance (Topic)

Language

English

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