CEP Discussion Paper No 1221
May 2013 (Revised January 2015)
A Question of Degree: The Effects of Degree Class on Labor Market Outcomes
Andy Feng and Georg Graetz
Abstract How does measured performance at university affect labor market outcomes? We show that degree class - a coarse measure of student performance used in the UK - causally affects graduates' industry and hence expected wages. To control for unobserved ability, we employ a regression discontinuity design that utilizes rules governing the award of degrees. A First Class (Upper Second) increases the probability of working in a high-wage industry by thirteen (eight) percentage points, and leads to three (seven) percent higher expected wages. The results point to the importance of statistical discrimination, heuristic decision making, and luck in the labor market.
Keywords: High skill wage inequality, regression discontinuity design, statistical discrimination JEL Classifications: C26, I24, J24, J31
This paper was produced as part of the Centres Productivity and Innovation Programme. The Centre for Economic Performance is financed by the Economic and Social Research Council.
Acknowledgements We thank Lucy Burrows from LSE Careers and Tom Richey from Student Records for their kind assistance with the data. We are indebted to Guy Michaels for his advice and encouragement throughout this project. We thank Johannes Abeler, Adrian Adermon, Joseph Altonji, Ghazala Azmat, Francesco Caselli, Marta De Philippis, Maarten Goos, Barbara Petrongolo, Wilbert Van der Klaauw, John Van Reenen, Felix Weinhardt, and seminar participants for helpful comments. All errors are our own. Graetz thanks the Economic and Social Research Council and the Royal Economic Society for financial support. The views expressed in this paper are those of the authors and do not necessarily reflect those of the Singapore Ministry of Trade and Industry.
Andy Feng, Senior Economist at Ministry of Trade and Industry, Singapore. Georg Graetz, Assistant Professor at Uppsala University. Associate at the Centre for Economic Performance, London School of Economics and Political Science and Research Affiliate at Institute for the Study of Labor.
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A. Feng and G. Graetz, revised 2015.
How does measured performance at university affect labor market outcomes? In this paper we estimate thecausal effect of degree class on graduates labor market outcomes. In the United Kingdom (UK) and otherCommonwealth nations, degree class is used as a coarse measure of performance in university degrees,and its importance is highlighted by the sizeable fraction of employers who report using the classificationin hiring decisions.1 It is not obvious that the classification system is useful because degree transcriptsprovide more information about applicant quality. However, detailed transcripts may be difficult tointerpret and to compare across students, leading employers to rely instead on the much simpler, five-stepdegree class measure when screening applicants. Given the coarseness of degree class, this may in turnlead to mismatch in the graduates labor market.
Identifying the effects of degree class is complicated by the fact that a naive comparison of, say,students who received a First Class with students who received an Upper Second could be biased by thediffering ability composition of the two groups. To isolate the casual effect of degree class we need toapproximate an ideal experiment and randomly assign degree class across students.
Using survey and administrative data from the London School of Economics and Political Science(LSE), we adopt a fuzzy regression discontinuity design (RD) which utilizes institutional rules governingthe award of degree class. Undergraduates at the LSE typically take nine courses over three years. Everycourse is graded out of 100 marks and fixed thresholds are used to map the marks to degree class. AFirst (Upper Second) Class Honors degree requires at least four marks of 70 (60) or above.2 We use thediscontinuous relationship between degree class and marks received on the fourth highest mark in our RD.This amounts to comparing students who barely made and barely missed a degree class within a narrowwindow of the marks received. We argue that this generates quasi-experimental variation needed for cleanidentification of degree class effects.
We find that higher degree classes positively affect a graduates probability to work in a high-wageindustry six months after graduation.3 A First Class increases the probability of working in a high-wageindustry by thirteen percentage points relative to an Upper Second. The corresponding estimate for anUpper Second, relative to a Lower Second, is eight percentage points. These effects translate into sizeabledifferences in expected wages. As we do not observe graduates wages directly, we use information fromthe Labour Force Survey (LFS) to assign wages by industry, gender, and year. A First Class is worthroughly three percent in expected starting wages. An Upper Second is worth more on the marginsevenpercent in expected starting wages. These results are robust to a battery of specification checks.
Our results suggest that employers rely on degree class when forming beliefs about graduates abilities.This is despite the fact that a graduates detailed exam grades are typically available to the employer aswellit appears that it would be too costly for employers to process and exploit this richer source ofinformation.
In further results, we find heterogenous effects by gender and by mathematical content of degree1Degrees are classified as First Class, Upper Second Class, Lower Second Class, Third Class, and Pass. This coarse measure
of performance stands in contrast to the much more detailed GPA measure used in the US. Degree class is also used by universitiesto screen applicants to postgraduate programmes.
2In terms of letter grades, a mark of 70 or higher would correspond to an A, while a mark between 60 and 69 would be a B.3High-wage industries are the top 20 percent (un-weighted) industries in our sample by log wages averaged across genders
programmes. A higher degree class increases the probability of working in a high-wage industry andexpected wages by more for males and for graduates of mathematical degree programmes.
We argue that a standard model of statistical discrimination can explain our findings of heterogenouseffects. In this model, employers cannot observe an applicants productivity directly. However, they canuse signals such as degree class to form beliefs about productivity. Employers attach more weight to thedegree class signal when the variance in ability is larger. We provide suggestive evidence that abilityvariance is higher among males and students of mathematical programmes in our sample.
The paper is related to the literature on the effects of performance in degrees on labor market outcomes.Using a differences-in-differences strategy, Freier, Schumann, and Siedler (2014) estimate a 14 premiumfor graduating with honors among German law graduates. In papers most closely related to this paper,Di Pietro (2010), Ireland, Naylor, Smith, and Telhaj (2009) and McKnight, Naylor, and Smith (2007)examine the effects of degree classification for students in the UK. Notably Di Pietro (2010) adoptsa regression discontinuity design using final year marks and finds no effect on employment. We getsimilar results on employment but extend the analysis by looking at wage differences. Ireland, Naylor,Smith, and Telhaj (2009) use OLS regressions and find 4 and 5 percent returns to First Class and UpperSecond degrees respectively. Their sample consists of a much larger dataset of UK students acrossmany universities and years but does not have the course history information we have to construct finercomparison groups.
Although concerned with university rather than high school graduation, our paper is similar to Clarkand Martorell (2014) in using the discontinuous relationship between exam scores and the probability ofreceiving an educational credential to implement a regression discontinuity design. Clark and Martorell(2014) estimate a zero effect of high school diploma receipt by comparing workers who barely passed tothose who barley failed high school exit exams in the US.
The aforementioned literature interprets earnings differences associated with degree class or highschool diplomas as pure signaling effects as in Spence (1973). We hesitate to follow this interpretation.We believe that our empirical strategy and similar ones in the literature are capable of establishingthe existence of information frictions in the labor market, which give rise to statistical discrimination.But these strategies do not necessarily distinguish between pure signalling and human capital theoriesof education. Evidence in favour of statistical discrimination is not necessarily evidence in favour ofsignalling. Statistical discrimination simply says that employers expect higher productivity if an applicanthas obtained some credential. The theory does not speak to the sources of these average productivitydifferences. In our context, it is conceivable that graduates with highe