Experimental Design Details
This is a comparative correspondence study assessing potential gender differences in hiring discrimination around parenthood in a low-, medium- and high-skilled occupation in two countries. Two sets of comparable application materials were developed for each occupation in each country based on national statistics, data bases, LinkedIn profiles, and discussions with country HR experts and recruiting professionals.
We use a 2x2 within-subject design for effects of parenthood. Two either female or two male sets of application materials will be sent in reply to employer job advertisements. All applicants are married; the treatment of interest is parental status. Parental status is randomly assigned and indicates that the applicant has one approximately 2-year-old child. In Finland, information on family status, along with the age of the child are frequently included among the personal information; we follow suit and signal parenthood and the age of the child by including it with contact information. It is less common to do this in the UK, but HR managers confirmed including family status in the personal information is still done occasionally, in part because the UK receives EU applicants that still follow this practice. We signal the UK child's *age* on the resume under personal interests indicating a hobby with a toddler.
Differences in callback rates between men and women are investigated by means of between-subject variation. Gender is manipulated through applicants’ names, which are clearly identifiable as male or female and selected from each country’s most common first names. In Finland and Germany, it is also usual to include a photo on the resume. Stock professional photos were purchased that approximated the age and expected professional attire of applicants for each occupation.
The definition of skill level follows the International Standard Classification of Occupations (ISCO), and is commensurate across the country-specific occupational classification schemes. High-skilled occupations usually require a tertiary qualification of 3 to 6 years, and include complex problem solving based on specialized knowledge; medium-skilled occupations involve complex technical and practical tasks and often require a post-secondary degree of 1 to 3 years; low-skilled occupations require only the first or possibly second stage of secondary education. The second criterion was that a substantial share of the workforce needed to be employed in the selected occupation. Larger occupations ensure that the number of vacancies is high and that each employer can be utilized only once to minimize the imposition on them. Third, the tasks in the selected occupations should not vary substantially across organizations or sectors. This ensures that the developed application materials would be suitable for the majority of job advertisements and more generalizable. The final selected occupations were accountants (high skill), restaurant managers (medium skill), and call center workers (low skill), based on sex composition, size of occupation, and nature of tasks across organizations. The design aimed for gender balance in each occupation in each country, to avoid conflating discrimination based on parenthood with that based on gender.
For internal validity, characteristics of applicants in each occupation which affect their hiring probability such as age, education and work experience must be kept constant. External validity requires that the applicants be as typical as possible for their occupation and life stage. Achieving internal and external validity in a cross-nationally comparative correspondence study assessing occupations with different skill levels raises particular challenges. For one, although educational requirements for each occupation are fairly comparable across countries by design, national differences in educational systems result in cross-country variation in the age at which applicants in the same occupation might enter as well as graduate from the educational system.
Another consideration is that the length of parents' employment histories is contingent on the age at which they likely entered parenthood, which varies with education. The cross-occupational average age at first birth ranges from almost 28 to almost 33 years among women, with highly-educated women in all countries becoming parents later than medium- and low-skilled ones.
To balance these aspects, we first harmonize according to mothers’ age at first birth in each country for each occupation, enhancing external validity that might affect employers’ perceptions. Second, to aid cross-country comparisons of occupations, we harmonized what we refer to as “total human capital” for each occupation across countries. We define total human capital as the sum of years in post-compulsory schooling plus work experience. Thus, while the length of education, or years of labor market experience in an occupation might differ slightly across countries, the two added together are harmonized for each occupation. Accountants thus have 12 years of post-secondary schooling and experience; restaurant managers 11, and call center workers 10.
A consequence of this two-step harmonization is that the age of applicants within the same occupation differs slightly across countries (~1 year). We justify the decision to harmonize education and experience rather than age because human capital is more salient to potential employers for young adults than age. HR managers and other recruiting experts confirmed the importance of commensurate education and experience over average age. Thus, any country-variation in positive callback rates for a given skill level likely stems from institutional effects rather than the (minor) cross-country variation in ages for each occupation.
Childless women and mothers of the same age may not have comparable years of work experience, however, as mothers tend to interrupt employment as a result of a birth. This raises the possibility that employers may discriminate against mothers not because of their status, but because they may have less experience at a given age than their childless peers. However, determining a plausible career-related interruption for the fictitious applicants is problematic. Not only do the selected countries differ in the length of parental leave, the duration of family-related employment interruptions varies substantially among women within a country. Furthermore, discussions with HR experts highlighted that parental leave that occurs during an ongoing employment episode is seldom itemized on the resume. For this reason, we follow existing studies and keep work experience between childless applicants and parents constant. Additionally, the employment trajectories on each occupational resume were made to be commensurate in career progression and accomplishments. The number of job moves is held constant, as is the size of the firms. Commensurate accomplishments further minimize the importance of deduced employment interruptions.
A final issue is that Finnish men are affected by mandatory conscription of six months to one year after secondary schooling. Consequently, a gap year was added to all Finnish medium- and high-skilled applicants between secondary and tertiary education. This gap accounts for men’s conscription, but works equally well for women, as it is common for all Finnish students to take a gap year before entry into higher education. Low-skilled men, in turn, are assigned six months of military service. Lower-skilled Finnish women are given six months in a job unrelated to call centers.
The commensurability of the application materials was validated via a series of lab and online validation experiments in the two countries.
The selected template of resume and cover letter, order of applications, and names of applicants are assigned randomly, whereas photos are assigned randomly to the Finnish resumes. If the posted job advertisement is more than 50 kilometers from the applicant’s listed home address, the software inserts an additional sentence in the cover letter, that the applicant is looking to move to the region to be closer to family.
Fielding began in the UK in August 2019, and in Finland in September 2019. The first month constituted a piloting phase to refine the types of jobs replied to and confirm that employers view the application sets as commensurate. We started fielding with software that took a random selection of job ads from several online employment websites, but quickly had to revert to using research assistants and the software proved unreliable. During lockdowns and in Finland, rather than a random sample, all suitable jobs were applied to. Top-level information was gathered relating to size of employer, sector, industry, nature of job (part-time), region, desirable special skills, and distance from applicant. The experimental data of interest are invitations to interview orinformal discussions relative to rejections.