1 / 14

Charles T. Clotfelter Helen F. Ladd Jacob L. Vigdor

Teacher Credentials and Student Achievement in High School : A Cross Subject Analysis with Student Fixed Effects. Charles T. Clotfelter Helen F. Ladd Jacob L. Vigdor Presentation at CALDER Conference, Oct. 4, 2007. Motivation . Focus on teacher credentials.

media
Télécharger la présentation

Charles T. Clotfelter Helen F. Ladd Jacob L. Vigdor

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Teacher Credentials and Student Achievement in High School: A Cross Subject Analysis with Student Fixed Effects Charles T. Clotfelter Helen F. Ladd Jacob L. Vigdor Presentation at CALDER Conference, Oct. 4, 2007

  2. Motivation • Focus on teacher credentials. • Lively policy debate about whether teacher credentials are predictive of student achievement. • Credentials are potentially important policy levers. • Focus on high schools • Compare use of administrative data sets to examine teacher credentials in the elementary grades

  3. North Carolina data • End-of- course (EOC) tests in high schools. -- Preferable for this purpose to the comprehensive exit exams used in many states -- Based on standard course of study -- Scores count for 25 percent of a student’s grade in the course. => Teachers have strong incentive to teach the material and students to learn it. • Availability of data on a wide array of teacher credentials.

  4. Approach • We use test scores on five tests typically taken by 9th or 10th graders: English I, algebra I, biology, geometry, and ELP (economic, legal and political systems) • Four cohorts of students matched to their specific teachers Students in 10th grade in 1999/2000; 2000/01; 2001/02; 2002/03 • Concern about selection into courses

  5. Models • Preferred model. Student achievement in subject S = f(teacher credentials and characteristics, classroom characteristics, student fixed effects) Student fixed effects VIP. They control for all subject-invariant characteristics of students, such as basic ability or motivation. Equivalent to expressing everything relative to the mean for that student (Some remaining technical concerns, but see paper) • Alternative model. No student fixed effects; but include student level time-invariant characteristics, such as race and gender.

  6. Strategy • Basic model and many variations on each credential to examine in detail the achievement effects of credentials. • All test scores are normalized by subject and year to have mean of 0 and s.d. of 1. . • Magnitude – for purposes of comparison. Effects of being black with low SES : -0.116 s.d. (From alternative model)

  7. Credentials I • Teacher experience (base = no experience) 2-3 years 0.050 6-12 years 0.061[not diff. from 0.050] (With addition of teacher fixed effects, coefficients rise with experience) • Teacher licensure (base = regular license) Lateral entry -0.061 other -0.046

  8. Credentials II • Master’s degree (base= no grad. degree) Received after 5 years of teaching 0.009 Comparable results for NC elementary teachers - 0.010 in reading • National Board Certification (base = never certified) • Pre-certification 0.022 • Cert. app. year 0.048 • Has certification 0.051 (sig. dif from 0.022) Compare NC elementary results. No human capital effect.

  9. Credentials III • Teacher test scores (base= within 1 sd of average) < 1 sd below average -0.027 > 1 sd above average +0.010 (By subject – matters most for math courses) • Teacher certification (base =no certification) -- in subject 0.081 -- in related subject 0.074 -- in other subject 0.012 (not sig.) (Disaggregated. Biggest for math and biology)

  10. Magnitudes • Predicted achievement difference for teacher at the 90th percentile compared to a teacher at the 10th percentile of the predicted achievement distribution 0.183 standard deviations Large effect Relative to class size reduction of 5 students – 0.013 Relative to SES effects (from alternative model) –0.116 But, nonetheless, credentials explain only 1/5 to 1/3 of the overall variation in teacher quality.

  11. Distributional concerns Uneven distribution of teacher credentials across high poverty schools, defined by poverty quartile Q 1 (high) Q4 (low) Non reg. license 20. 5 % 13.3 % Lic.test score –0.057 0.117

  12. Across classrooms – algebra I

  13. Distributional effects • Consider black vs. white differences in teacher credentials in algebra 1 multiplied by estimated achievement effects. Across a large number of credentials – total adverse effect on black achievement = <0.02 • May seem tiny, but looms larger relative to the coefficient for a black student (controlling for other factors) of -0.057 => Maldistribution of teachers contributes to black-white achievement gap.

  14. Conclusions • Teacher credentials matter in high school • Aggregate effects are quite large • Some differences with findings at the elementary level. E.g. master’s degree; National Board Certification • Uneven distribution of teacher credentials across students by race contributes to the black-white achievement gap.

More Related