Skip to main content
eScholarship
Open Access Publications from the University of California

Scholarly Works (5 results)

  • Thesis
  • Peer Reviewed
UC Berkeley Electronic Theses and Dissertations (2011)

Health and education are two important issues in developing economies. Field and natural experiments provided me with great opportunities for identifying the effects of health insurance and incentive on doctors' prescribing behaviors and the peer influences among students.

The first chapter examines whether doctors write more expensive prescriptions for insured patients and if so, why. I conducted a randomized audit experiment using undercover visits to Chinese hospitals. The results show that prescriptions for insured patients are 43% more expensive than those for uninsured patients when doctors expect to obtain a proportion of their patients' drug expenditures. The differences in prescriptions are largely explained by a differential agency problem hypothesis that doctors act of self-interest and prescribe more unnecessary or expensive drugs to insured patients, rather than by a considerate doctor hypothesis that doctors consider the trade-off between drug efficacy and patients' ability to pay.

The second chapter studies peer effects in a natural experiment generated by an unusual change in college admission policy at a prestigious Chinese university. The change in admission policy brought a large number of low-scoring students into several academic departments which only admitted high-scoring students in usual years. Exploiting the large variations in peer characteristics and the strong interactions among peer groups, the analysis finds that specially admitted low-scoring students significantly reduced the performance of regular students in standardized English tests. This detrimental effect of specially admitted students is concentrated among students with English ability below average.

Most research on peer effects in pre-college education focuses on the class or school level and assumes that students are influenced by class- or school-level averages. The third chapter examines peer effects within small groups inside classrooms by exploiting an experiment with random seat assignments inside Chinese classrooms. We define peers as either deskmates or neighboring students who sit at desks directly in front of or behind the students. The results suggest different patterns of impacts from deskmate and other neighboring students: female deskmates improve test scores for both boys and girls while the proportion of females among other neighboring students has strong positive effects on girls but no impact on boys. Overall, the results suggest that organizing students into small groups of homogeneous gender inside a classroom - a small-scale version of single-sex education - can significantly improve test scores.

    Cover page: Experiments on Health and Education in Developing Economies
    • Article
    • Peer Reviewed
    UC Berkeley Previously Published Works (2017)
    Employers and colleges value individuals with leadership service, but there is limited evidence on whether leadership service itself creates skills. Identification in this context has proved di cult because settings in which leadership service accrues to individuals for ostensibly random reasons are rare. In this study we estimate the e ects of random assignment to classroom leadership positions in a Chinese secondary school. We find that leadership service increases test scores, increases students’ political popularity in the classroom, makes students more likely to take initiative, and shapes students’ beliefs about the determinants of success. The results suggest that leadership service may impact human capital and is not solely a signal of preexisting skills.
      • Article
      • Peer Reviewed
      UC Berkeley Previously Published Works (2015)
      Many believe that classroom interactions play an important role in students’ academic achievement, but there is little evidence on peer effects within subclassroom groups. We exploit random seat assignment in a Chinese middle school to estimate how the gender of neighboring students affects a student’s academic achievement. We find that being surrounded by five females rather than five males increases a female’s test scores by 0.2-0.3 standard deviations but has no significant effects on a male’s test scores. These results suggest a low-cost way to potentially improve performance within the world’s largest school system.
        • Article
        • Peer Reviewed
        UC Berkeley Previously Published Works (2019)

        Objective

        To determine the implications of car ownership for physical activity and weight in a global city.

        Design

        Quasi-experimental cross sectional study.

        Setting

        Beijing, China, 2011-15.

        Participants

        People aged 18 and older from a random sample of households who had entered a permit lottery to purchase a vehicle between January 2011 and November 2015.

        Interventions

        Permit allowing purchase of a vehicle within six months of permit issuance.

        Main outcome measures

        Transit use (number of subway and bus rides each week), physical activity (minutes of walking or bicycling each day), and weight, measured once in early 2016.

        Results

        Of 937 people analysed in total, 180 had won a permit to purchase a new vehicle. Winning the permit lottery resulted in the purchase of an additional vehicle 91% of the time (95% confidence interval 89% to 94%; P<0.001). About five years after winning, winners took significantly fewer weekly transit rides (-2.9 rides (-5.1 to -0.7); P=0.01) and walked and cycled significantly less (-24.2 minutes (-40.3 to -8.1); P=0.003) than those who did not win the lottery. Average weight did not change significantly between lottery winners and losers. Among those aged 50 and older, however, winners' weight had increased relative to that of losers (10.3 kg (0.5 to 20.2); P=0.04) 5.1 years after winning.

        Conclusions

        These data indicate that vehicle ownership in a rapidly growing global city led to long term reductions in physical activity and increase in weight. Continuing increases in car use and ownership in developing and middle income countries could adversely affect physical health and obesity rates.
          • Article
          • Peer Reviewed
          UC Berkeley Previously Published Works (2016)
          Congestion plays a central role in urban and transportation economics. Existing estimates of congestion costs rely on stated or revealed preferences studies. We explore a complementary measure of congestion costs based on self-reported happiness. Exploiting quasi-random variation in daily congestion in Beijing that arises because of superstitions about the number four, we estimate a strong effect of daily congestion on self-reported happiness. When benchmarking this effect against the relationship between income and self-reported happiness we compute implied congestion costs that are several times larger than conventional estimates. Several factors, including the value of reliability and externalities on non-travelers, can reconcile our alternative estimates with the existing literature.
            Top