15
3. Tests of H1
—Life History Strategies of College Attendees versus Non-Attendees
3.1. Data Data for testing H1 are from the National Longitudinal Survey of Youth NLSY.
7
The NLSY is a survey of roughly 10,000 randomly-selected Americans born between 1957 and 1964.
It begins in 1979 and has been updated 24 times through 2012 to track participants ’ ongoing labor
market activities and other significant life events. This dataset captures educational and career activities, as well as self-reported lifestyle attributes and choices. It is an ideal dataset for testing
H1, because it allows linkage between indicators of early childhood SES, adolescent and adult lifestyle attributes, and educational and career choices.
3.2. Variables
College attendee
is our proxy for a person’s choice to pursue a college degree. We define a
college attendee
as a respondent in the NLSY who had completed at least four years of college by the age of 26.
8
To proxy for
low SES
, we identified respondents whose parents had not attended any college when the survey began in 1979. Parental education level is a widely-accepted proxy
of SES, as it is positively associated with income and negatively associated with student loan debt and full-time work as a source of tuition assistance DeAngelo et al. 2011.
To find proxies for life history strategy speed, we search for variables that are both available
during the appropriate time in participants’ lives late adolescence and early adulthood when people also make career decisions and relevant to our theory. We find five variables from
the NLSY that are available in relevant years and that theory suggests will be sensitive to the speed
7
See http:www.bls.govnlsnlsy79.htm
and Appendix B for more information about the NLSY. We use the NLSY in tests of H1 but not in other tests, because the NLSY does not measure the degrees pursued by respondents attending
college and graduating from college.
8
We repeated our tests with college attendee defined as anyone who completed one year of college by the age of 22, to proxy some college attendance as opposed to attendance and completion. We choose to emphasize the standard of
completing four years by age 26, as it seems more relevant to our labor market self-selection theory to focus on those who complete college, but our inferences are the same using either proxy.
16 of a
life history strategy
. We use
average age at first marriage
, with older ages signifying a slower strategy Chisholm 1993, 9;
average age at birth of first child
, with older ages signifying a slower strategy Griskevicius et al. 2011b, Nettle 2010;
average number of children
, with fewer children signifying a slower strategy Nettle 2010; whether the respondent has
smoked daily
at any time in their life, with not smoking signifying a slower strategy Petridou et al. 1997; Hill and Chow 2002;
and the
age
at which the respondent began smoking daily, with older ages signifying a slower strategy Petridou et al. 1997; Hill and Chow 2002.
3.3. Results We use a difference in difference analysis to test H1. Using the variables above, we
partition the sample into four groups: 1
college non-attendees
who are
low SES
, 2
college attendees
who are
low SES
, 3
college non-attendees
who are
high SES
, and 4
college attendees
who are
high SES
. H1 is supported by larger differences between
college attendee
and
non- attendee
differences when socioeconomic status is low than when it is high, i.e., the difference between groups 1 and 2 is greater than the difference between groups 3 and 4.
Table 1 shows that all five
slower life history strategy
proxies are consistent with
low SES college attendees
being significantly more likely than
low SES college non-attendees
to have made choices consistent with a slow life history strategy all p
≤ 0.02.
9
Further, there are five difference in differences in Table 1 to test whether the difference between
college attendees
and
non- attendees
is greater for
low SES
than for
high
SES. The difference between
college attendees
and
college non-attendees
is significantly greater for
low SES
respondents than for
high SES
respondents on four of the five measures p ≤ 0.09. The result for
smoked daily
is directionally consistent with our predictions but not statistically significant p = 0.13.
9
Hypothesis test p-values are one-tailed, because our predictions are directional.
17 Our results support H1 that
college attendees
from low SES backgrounds have especially slow life history strategies. Further, among
college attendees,
our results are consistent with
low SES
individuals exhibiting even slower strategies than
high SES
individuals on
average number of children
p = 0.03 and
smoked daily
0.07. Thus, the pool of low SES people minimally eligible to select into accounting are predominately those with slow life history strategies. This point is
critical in examining determinants of entry into accounting, as we theorize that distinguishing features of accounting likely make it appealing to people pursuing slower strategies.
4. Experimental Tests of H2 and H3
Kategori