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College major choice and beliefs about relative ability: an experimental intervention to understand gender gaps in STEM
Initial registration date
October 11, 2019
October 11, 2019 11:29 AM EDT
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University of Michigan
Other Primary Investigator(s)
Additional Trial Information
Despite earning more than half of all college degrees, women remain persistently underrepresented in many quantitative fields such as computer science, engineering, and economics. Previous research suggests that women hold biased beliefs about their own relative ability in math-intensive fields. In particular, women may underestimate their own performance or ability and overestimate how high they must perform to pursue a major in science, technology, engineering, math, or economics (STEM). This information friction could be leading them to inefficiently avoid entering and remaining in STEM. Using students in large introductory STEM courses across seven disciplines at a large university, this study randomly provides students with information about their performance relative to their classmates and relative to STEM majors (Treatment 1); a subset of high-performing students receive additional encouragement emphasizing their STEM potential (Treatment 2). I measure how students update their beliefs about relative performance in response to the treatments, and how their subsequent behavior such as course-taking and major choice changes. The experiment allows me to test how beliefs matter for major choice and how students update their beliefs to incorporate new information. By measuring gender differences in these mechanisms, I will contribute to understanding gender differences in college major choice and policies that may or may not be successful in narrowing gaps. By measuring differences across the seven fields where I implement the intervention, I will contribute to the thus far limited knowledge of how gender dynamics vary across STEM fields.
Owen, Stephanie. 2019. "College major choice and beliefs about relative ability: an experimental intervention to understand gender gaps in STEM." AEA RCT Registry. October 11.
Intervention Start Date
Intervention End Date
Primary Outcomes (end points)
My key outcome is persistence in a STEM major, which I operationalize as short-term, medium-term, and long-term outcome variables: (1) taking STEM courses in subsequent semesters (short-term); (2) declaration of a major in STEM (medium-term); and (3) graduation with a STEM degree (long-term).
Primary Outcomes (explanation)
Secondary Outcomes (end points)
Secondary outcomes: short-term stated intentions/interest in STEM; beliefs about own relative performance; beliefs about STEM major performance; beliefs about potential for success as a STEM major; performance on final exam and in course. The key sources of heterogeneity I will test for are by gender and field.
Secondary Outcomes (explanation)
Students will be randomly assigned to receive one of three messages, with randomization depending on students’ mid-semester performance. Based on mid-semester grades, students will be categorized into above- or below-median performance. Students performing below the median will be assigned to either the information-only message (T1) or the control message (C); those performing above the median will be assigned to either the information-only message (T1), the information-plus-encouragement message (T2), or the control message (C).
Experimental Design Details
Randomization done in office by a computer
Was the treatment clustered?
Sample size: planned number of clusters
10,000 students (approx.)
Sample size: planned number of observations
10,000 students (approx.)
Sample size (or number of clusters) by treatment arms
4167 students control (approx.); 4167students treatment 1 (T1, info only); 1667 students treatment 2 (T2, info + encouragement)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Outcome 1 (taking a STEM course in subsequent semester): MDE = 2.17 percentage points (2.5%)
Outcome 2 (declaring a STEM major 3 semesters later): MDE = 2.98 ppt (6.6%)
Outcome 3 (graduating with a STEM degree): MDE = 2.72 ppt (9.7%)
INSTITUTIONAL REVIEW BOARDS (IRBs)
University of Michigan Health Sciences and Behavioral Sciences Institutional Review Board
IRB Approval Date
IRB Approval Number