Walsh, FrankFrankWalsh2016-10-122016-10-122013 Elsev2013-06Economics Lettershttp://hdl.handle.net/10197/8042We use longitudinal data from an Irish household survey to measure the union wage premium.  A sub-sample where the worker's payslip was seen by the interviewer is unlikely to have measurement error for the union variable.  The results support the finding that measurement error leads to a large downward bias in fixed effects estimates of the union effect but indicate that ability bias has a small effect on the average union wage premium.enThis is the author’s version of a work that was accepted for publication in Economics Letters. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Economics Letters (VOL 119, ISSUE 3, (2013)) DOI: 10.1016/j.econlet.2013.02.034.Union wage premiumAbility biasMeasurement errorJournal Article119329629810.1016/j.econlet.2013.02.0342016-09-19https://creativecommons.org/licenses/by-nc-nd/3.0/ie/