Experimental Design Details
We propose to conduct our experiment at the beginning of the bi-semester 2022-2023 with students enrolled in the 7 sections of Principles of Microeconomics course. The experiment will be conducted in the first class of the course. We will randomly divide all students into four equal groups, and each of these groups will sit together in their assigned classroom only for that one class.
This first class, which will incorporate our intervention, will not be conducted by their regular instructor. The session will be for 1 hour and 15 minutes, where students will attend a recorded video lecture which will introduce them to the early concepts in economics for 20 minutes, students will then take an 8 question multiple choice question quiz for 10 minutes, and will then fill the teaching evaluation (13 questions mapping into 6 broader teaching dimensions discussed above) and demographics form (information on age, gender, programme of study, major, parental education, household income-bracket, etc.), ending with the beliefs survey about their perception of social norms about male/female's appropriateness as professors, and their belief about role of an individual's weight as an impediment in their success. The belief survey will specifically ask students about their expected grade in the course, about how they think male students generally perceive the appropriateness of a male and of a female as professors. Similarly, how female students generally perceive the appropriateness of a male and of a female as professors. We will also ask them three questions about how they perceive fat people (asking them to rate their belief about: whether "fat people cannot be successful as others", "fat people cause their own problems by not exercising", "fat people have different personalities than other people"). These questions are asked in order to see whether students' perception of social norms with respect to the appropriateness of the gender of a professor or his/her weight affects how the student rates that professor.
Quiz, teaching evaluation and demographics questions will be asked anonymously over Google Form after the 20 minutes audio lecture , without asking for subject's name or university id. Students will be articulately informed that as instructors, we are interested in their average understanding of the topic and their average feedback of the instructor, and therefore, all the information being collected is anonymous.
The four groups created in the experiment will include T1: Male-Normal weight type, where a male instructor with normal looking weight will teach. The other treatment groups include T2: Female-Normal weight type, where a female instructor with normal looking weight will teach; T3: Male-Overweight type, where a male instructor with observably overweight weight body type will teach; and T4: Female-Overweight type, where a female instructor with observably overweight weight body type will teach.
In each treatment, the instructor will start by introducing himself/herself for two minutes, before starting with the lecture. The information introducing the instructor will include instructor's PhD granting institution (a US university name used to reflect the typical internationally education faculty at this institution), teaching experience, research interests, and professional service engagement. We will use hypothetical names for the instructors (Amit Agarwal for male and Sunita Sharma for female), and the information curated will be such that it reflects the profile of a typical young faculty teaching such courses at the university. The experiment, however, will be conducted like a natural field experiment and students will not know the hypothetical nature of such information. This is to prevent any bias that provision of such information may cause with their regular instructor for the course. Students will, however, be sent a debriefing email at the end of the experiment informing them of the intent of the study, and to request their consent allowing us to use their data in the study.
In order to estimate the causal effect of gender*weight, we record the lecture by a course instructor, and modulate the voice using a software to create a male and a female version of the same lecture. We do not use the lecture recorded in the original voice. This design aspect ensures that teaching style and effectiveness is same in all four groups.
This implies that the differences between T1 and T3 groups' SET scores are attributed to weight differential among male instructors of otherwise identical teaching capabilities. Similarly, differences between T2 and T4 groups' SET scores are attributed to weight differential among female instructors of otherwise identical teaching capabilities.
Since the teaching is identical across the four groups. A difference between T1 and T2 will be indicative of gender-bias in SET scores by students when the instructors are normal-weight type. A difference between T3 and T4 will be indicative of gender-bias in SET scores by students when the instructors are overweight type.