Macro-level data on labour market discrimination sometimes fail to disentangle the real explanations of gender inequality, i.e. differences in the professional capabilities, average performance and aspirations vs. pure discrimination against women. Experimental designs, such as vignette studies, can be a useful tool to control for those variables that, in the real world, are usually linked to endogeneity issues and selection biases (e.g. motherhood and adoption of work-life balance strategies such as reducing work hours).

To our knowledge, the present study represents the first attempt to assess the evidence of discrimination in promotion processes against mothers in the Spanish labour market using a vignette study. A vignette study is a particular type of survey-based experimental design, which tries to expose respondents (in our case, employers with supervisory responsibilities) to a particular reality-inspired treatment (candidates who are mothers), by rating fictitious situations (potential candidates for a promotion).

We hypothesize that mothers are subjected to “paternalistic stereotypes” which portray them as “warm” but “incompetent” and thus less interesting for a promotion. Other characteristics (such as skills or experience) being equal, it could be concluded that mothers in this case would be subject to discrimination. We also hypothesized that motherhood could be particularly costly when combined with the adoption of work-life balance measures (i.e. reducing work hours or teleworking).

To test these hypotheses, an e-mail survey was administered to managers /supervisors inside companies belonging to three industries in Spain (a male-dominated one, a female-dominated one and a mixed one). Preliminary findings seem to suggest that, even if there is not a generalized motherhood penalty as such, particular groups of employers (such as male recruiters or those working in female-dominated industries) might be particularly reluctant to promote mothers, in comparison to fathers or childless women.