Beyond the Griliches biases
International Journal of Manpower
ISSN: 0143-7720
Article publication date: 3 June 2024
Issue publication date: 29 August 2024
Abstract
Purpose
The paper investigates the determinants of the Ordinary Least Squares (OLS) bias of the wage return to graduate education for high-school workers in Portugal.
Design/methodology/approach
The study uses matched employer-employee data for Portugal, over the 2002–2012 period, to estimate a wage-schooling model that controls not only for individual observed characteristics, firm observed characteristics and year fixed effects, but also for three high-dimensional vectors of fixed effects – one for employees, one for employers and one for job titles.
Findings
The main results are the following. First, disregarding individual fixed effects is highly problematic, accounting for 48.5% of the OLS bias. Second, disregarding firm fixed effects is also problematic, accounting for 12.3% of the OLS bias.
Research limitations/implications
The implication for the studies in the labor-supply literature that estimate, by means of instrumental variables, the wage returns to in-school work or to on-the-job schooling is that an instrument dealing with employee’s unobserved ability only may fail to meet the exclusion restriction.
Practical implications
Take the typical instrument based on a policy reform that changes the compulsory schooling level in the population. This instrument may well be argued to be correlated with the education of the employee and uncorrelated with the unobserved ability of the employee, but unfortunately it cannot be seen as orthogonal to the unobserved ability of the employer because of its correlation with the (unobserved) education of the manager. This is a simple corollary of the fact that the employee and the manager belong, in general, to the same population.
Social implications
Individuals invest a considerable amount of resources in education, which is seen to have positive effects on several dimensions of individual life. Yet, the estimation of these effects is still surrounded by technical difficulties.
Originality/value
To the best of the authors’ knowledge, this is the first study that uses the Gelbach decomposition to investigate the determinants of the OLS bias of the wage return to graduate education for high-school workers.
Keywords
Acknowledgements
Besides the institutions of employment, Corrado Andini is also affiliated with CEEAplA (Centre of Applied Economic Studies of the Atlantic, Portugal), IZA (Institute of Labor Economics, Germany) and GLO (Global Labor Organization, Germany). He thanks, without implicating, the Economics and Research Department at the Bank of Portugal for kind hospitality and access to QP data during a sabbatical leave. Monica Andini acknowledges useful comments from her colleagues of the Structural Economic Analysis Directorate at the Bank of Italy. The views expressed in this paper do not necessarily reflect those of the institutions which the authors are affiliated with. The usual disclaimer applies.
Citation
Andini, C. and Andini, M. (2024), "Beyond the Griliches biases", International Journal of Manpower, Vol. 45 No. 7, pp. 1409-1425. https://doi.org/10.1108/IJM-08-2022-0378
Publisher
:Emerald Publishing Limited
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