The college double major and subsequent earnings

Abstract

In this study I examine the relationship between graduating from college with two majors rather than one and labor market earnings using the 2003 National Survey of College Graduates. Because institutions are heterogeneous both in terms of overall quality and in the availability of opportunities to double major, I attempt to control for such overarching institutional differences and explore their effects on premiums to completing a double major. On average, I find a double major to earn 3.2% more than his/her single major counterpart. I also find evidence that premiums to double majoring differ across types of institutions: ranging from a near 4% premium at Research and Comprehensive universities to no effect at Liberal Arts colleges. Finally, I investigate the degree to which choices of first and second major academic disciplines affect earnings premiums.

Keywords:

• double major
• earnings return

Acknowledgements

Thanks to Dave Marcotte, Lisa Dickson, and two anonymous referees for very helpful comments and suggestions. Of course, any errors and all opinions are the author's own.

Notes

1. For a good exposition of the development of this particular literature, see Zhang (2005).

2. The vector of race and ethnicity dummies is derived from a variable that treats the ‘Hispanic’ ethnicity category as mutually exclusive to the other race categories.

3. These survey‐specific probability weights are provided in the 2003 NSCG.

4. Carnegie Foundation for the Advancement of Teaching's (2006) ‘Basic Classification Technical Details’ – see http://www.carnegiefoundation.org/classifications/index.asp?key=798.

5. The eight classifications are: Research I, Research II, Doctorate Granting I, Doctorate Granting II, Comprehensive I, Comprehensive II, Liberal Arts I, and Liberal Arts II.

6. These differences in weighted sample mean proportions are each statistically significant at the 1% level: comparisons of the future decade's mean proportion of double majors with the preceding decade's mean proportion of double majors yield z‐scores of −9.18, −12.87, and −6.14, respectively, for the sample including graduate degree holders, and z‐scores of −8.03, −10.23, and −5.32, respectively, for the sample containing only Bachelor's degree holders.

7. The relevant premium point estimates and standard errors are as follows: an Education first major who adds any second major (Table 3, column (4) model) can expect an insignificant premium of 0.012 (0.029), and an individual adding an Education field as a second major to a given first major (Table 3, column (5) model) can expect an insignificant premium of −0.007 (0.027).

8. It should be noted that three of the four double major dummy point estimates are nearly the same (Research, Doctorate Granting, and Comprehensive), yet in the case of Doctorate Granting institutions, the associated standard error is over 50% larger, accounting for its insignificance. Clearly there is a different premium to double majoring at a Liberal Arts school, compared with the rest.

9. The estimates obtained using the ‘Bachelor's Only’ sample in place of the ‘Graduate Degree Holders’ sample are similar in all respects.

10. All reported mean proportions of double majors are weighted using the final probability weight provided by and specific to the 2003 NSCG.

11. In the context of an unrestricted model, the gender dummy and all interactions are jointly significant at the 1% level (F = 19.64).

12. As I am mainly interested in direct earnings benefits to double majors, I choose to use the ‘Bachelor's Only’ sample here. Yet, all results are qualitatively the same if I switch to the ‘Graduate Degree Holders’ sample.

13. The t‐statistic from a two sample t‐test equals 0.47.