Unanswered Questions In Economics

[Custodio Groves]

Thisis a list of some of the major unsolved problems, puzzles, or questions in economics. Some of these are theoretical in origin and some of them concern the inability of orthodox economic theory to explain an empirical observation.

Women are underrepresented at all levels within the discipline, a fact that has persisted for decades. Studies documenting the gender gap in introductory courses consistently place the female enrolment at less than 50%, with many documenting percentages between 40% and 45%, across all institution types in the United States (see, e.g., Rask and Tiefenthaler 2008; Main and Ost 2014; Emerson and McGoldrick 2019). The gender disparity grows by graduation, with the percentage of bachelor degrees awarded in the United States to females peaking at 35% in 2003 and then falling below 30% for most institutional categories thereafter (Bayer and Wilcox 2019; Siegfried 2021).

Female enrolment in degree-granting post-secondary institutions climbed above 50% in 1979 and has been steadily increasing since. Most recently available figures place female enrolment in 2020 at 58.6%.3 Despite their growing presence in colleges and universities, female students neither enrol in introductory economics courses at the same rate nor has the growth pattern of their enrolment mirrored that of institutional enrolment figures. Reported enrolment percentages of female students in introductory economics courses are below 50%, consistent over time and by institution type. For example, several studies suggest that the percentage of females ranges from 44% to 49% at research institutions (Elzinga and Melaugh 2009; Main and Ost 2014; Owen 2010), 40% at large schools with engineering programs (Emerson and McGoldrick 2019), 43% at mid-sized state schools (Hadsell 2020), 46% at liberal arts colleges (Rask and Tiefenthaler 2008), and 47% at Canadian institutions (Anderson, Benjamin and Fuss 1994).

In one of the few multi-institution studies, Emerson, McGoldrick and Mumford (2012) identify patterns based on 587,991 students at 11 engineering schools.4 Similar to other studies, 49% of male students took an introductory economics course versus 38% of female students. Of those who took introductory economics, 2.7% of males and 1.9% of females took an intermediate course. However, the gender differential reverses at graduation. About 20% of males and 23.3% of females that took the introductory course ultimately graduated with an economics major.5

In this section we outline primary reasons given for the gender gap based on the current research. As will become clear, no single reason dominates and any approach to closing the gap will have to take this into account.

It would be nave to think that broader gender issues within the profession are not related to why we fail to see more women in our classrooms. Some issues are obvious: a dearth of female faculty means few female role models. Other issues may be less obvious. For example, it may be that the aggressive or competitive environment that economists bring to seminars and other settings translate to how they conduct their classrooms.

Graduate school is a trying time for most students, but research suggests it is even more so for female students. Colander and Holmes (2007), using data from 231 graduate students at seven elite PhD programs, report that over half of female graduate students, compared to a quarter of male students, find the coursework to be very stressful, and female graduate students are 23 percentage points less likely to choose to attend graduate school if they were currently making that decision.6

The principles class is the gateway class to economics, which explains why it attracts attention when discussing issues of diversity within the profession. Yet, there is evidence that female students arrive on college campus less interested in economics. Tonin and Wahba (2015) use data from the UK to analyze a 50% random sample of all college applications in 2008. They find that female applicants are less likely to apply for a degree in economics. This result holds even for females satisfying the math requirements to apply to economics. This suggests that, to close the gap in economics, work must be done to enhance interest prior to their arrival on campus. This matters because initial major matters. Owen and Hagstrom (2021) find that students at a liberal arts school expressing an interest in majoring in economics at the time of admission are 36 percentage points more likely to express interest after a second economics course. Similarly, Ahlstrom and Asarta (2019) find that male and female students with a declared economics major at the time they entered the institution were more likely to persist to the second introductory course (macroeconomics) and those having a declared economics major at introductory macroeconomics were more likely to take intermediate microeconomics.

Economics seminars and graduate education, as previously noted, can be viewed as competitive and aggressive. If this culture permeates the undergraduate classroom, then students on the margin may feel even more marginalized. In our discussion of belonging below, we will see that it is not uncommon for female students to feel less like they belong. One way to counter this is to purposefully create a cooperative classroom environment by employing team-based and other cooperative learning approaches. Espey (2018) analyzes 114 teams with almost 700 students in 17 introductory microeconomics classes. She introduces team-based learning and finds that the level of cooperation within teams improves the performance of female students and has no measurable effect on the performance of male students.

What do these differences mean for the economics major? Goldin (2015) finds that math aptitude does not appear to explain differences in major choice. As previously noted, Tonin and Wahba (2015) find that female students with a needed math requirement were still less likely to choose an economics major, suggesting it is not math that is keeping them out. Emerson, McGoldrick and Siegfried (2018) find that a one-semester calculus requirement for economics majors increases the number of female students, but a two-semester requirement has the opposite effect at PhD-granting universities while still attracting more female majors at liberal arts colleges. However, Ahlstrom and Asarta (2019) report that, conditional on having completed intermediate microeconomics, male students with higher SAT math scores have a greater likelihood of securing a Bachelor of Science (BS) in economics and a lower probability of minoring in economics. Higher SAT math scores for females decrease their likelihood of graduating with a Bachelor of Arts (BA) in economics.

In this section we provide an overview of research associated with interventions that might be loosely categorized as information nudges, new courses offerings, active learning pedagogy, and providing role models and other department-wide interventions. We focus our review primarily on studies that include analysis that goes beyond controlling for sex, summarizing empirical studies that isolate treatment impacts by sex. While the overall focus of this paper is on increasing participation of women in the major, we include performance outcomes in this section as elsewhere we note findings that indicate differences in grade sensitivity by sex. Thus, differences in performance outcomes might ultimately translate into persistence differences and suggest a fruitful avenue for future research.

While studies measuring the impact of pedagogic interventions on student outcomes are more common than either incremental or extensive curricular overhauls, not all control for gender, and few include an analysis that might identify sex differences in outcomes of interest. Here again we include studies that fall short of measuring impacts on course-taking and majoring in economics as they provide a basis for future research on pedagogic innovations that investigate sex differentials in persistence.

Classroom experiments are the most studied pedagogic technique in economics, but most studies only include gender as a control variable (with no interaction terms). Two notable exceptions provide mixed evidence as to whether outcomes differ by gender.

Much of the literature associated with cooperative learning is descriptive, identifying key tenets and providing examples of implementation (see, e.g., Bartlett 1995; Maier and Keenan 1994; Maier, McGoldrick and Simkins 2011; McGoldrick et al. 2010). Of the empirical studies measuring efficacy and impact on attitudes (Marburger 2005; Yamarik 2007; Emerson, English and McGoldrick 2015, 2016, 2018) only one provides insight into gender differences associated with cooperative learning interventions. Emerson, English and McGoldrick (2015) compare student outcomes in a cooperative learning class (think-pair-share) to those in a lecture environment with identical independent problem-solving exercises. While they find no performance differences associated with the pedagogy overall (suggesting that the problem-solving nature of the exercises is more important than the mechanism by which they are implemented), they find that females in cooperative learning sections earned higher course scores than males.

Team-based learning (TBL) is a carefully constructed approach that includes purposefully constructed cooperative learning groups, pre/during/post class accountability, and structured engagement activities (Ruder, Maier and Simkins 2021). In one of the few studies that analyzes outcomes for courses other than introductory undergraduate economics, Hettler (2015) includes students across principles courses and (undergraduate and MBA level) quantitative methods courses. They find a small positive and significant impact of TBL on course grade, but TBL had no gender differential impact.

While the flipped classroom approach may have originated with Lage and Treglia (1996), it has continued to evolve and has been much studied at the introductory course level. Unfortunately, there is no evidence that female students perform better in flipped classrooms. Caviglia-Harris (2016) uses a quasi-experimental design to compare traditionally taught courses and two versions of a flipped course (partial and full) in microeconomics principles. Although both versions of the flipped course increased scores on the final examination, neither had a significant differential impact by sex. In another quasi-experimental design study consisting of students across two flipped and two control sections of a principles of microeconomics course over a three-year period, Craft and Linask (2020) analyze measures of performance throughout and at the end of the course. They find no significant differences by gender for the flipped class in comparison to the traditional lecture for all measures: graded problem-solving questions, the final exam, course grade, and TUCE post-test gap-closing measures.

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