A Community College Instructor Like Me: Race and Ethnicity Interactions in the Classroom

Detailed administrative data from a large and diverse community college are used to examine if academic performance depends on whether students are the same race or ethnicity as their instructors. To identify racial interactions and address many threats to internal validity we estimate models that include both student and classroom fixed effects. Given the large sample sizes and computational complexity of the 2-way fixed effects model we rely on numerical algorithms that exploit the particular structure of the model’s normal equations. Although we find no evidence of endogenous sorting, we further limit potential biases from sorting by focusing on students with restricted course enrollment options due to low registration priorities, students not getting first section choices, and on courses with no within-term or within-year racial variation in instructors. We find that the performance gap in terms of class dropout rates, pass rates, and grade performance between white and underrepresented minority students falls by 20-50 percent when taught by an underrepresented minority instructor. We also find these interactions affect longer term outcomes such as subsequent course selection, retention, and degree completion. Potential mechanisms for these positive interactions are examined.

A Community College Instructor Like Me: Race and Ethnicity Interactions in the Classroom

This paper uses detailed administrative data from one of the largest community colleges in the United States to quantify the extent to which academic performance depends on students being of similar race or ethnicity to their instructors. To address the concern of endogenous sorting, we use both student and classroom fixed effects and focus on those with limited course enrolment options. We also compare sensitivity in the results from using within versus across section instructor type variation. Given the computational complexity of the 2-way fixed effects model with a large set of fixed effects we rely on numerical algorithms that exploit the particular structure of the model's normal equations. We find that the performance gap in terms of class dropout and pass rates between white and minority students falls by roughly half when taught by a minority instructor. In models that allow for a full set of ethnic and racial interactions between students and instructors, we find African-American students perform particularly better when taught by African-American instructors.race, education, minorities, college

Economic Justice and Welfare for All

Translation of:Reichtum der Welt - für alleThe title of the book promises ‘welfare for all’. Of course, that does not mean luxury for all. No, that would be an endless waste that cannot be in anyone’s interest. What is meant is something realistic, namely a reasonably fair participation of all people in the infinite and indescribable wealth of our God-given world. Each person, without exception, can be empowered as a human being to lead a self-determined, decent life, ‘prospering to freedom’. The basic idea is simple: the more people there are on earth, the more capable humanity is to make meaningful contributions to a meaningful whole. Motivated human resources are available on a massive scale

Dynamic multitasking and managerial investment incentives

status: publishe

Partial Clustering in Binary Two-Dimensional Colloidal Suspensions

Strongly interacting binary mixtures of superparamagnetic colloidal particles confined to a two-dimensional water-air interface are examined by theory, computer simulation and experiment. The mixture exhibits a partial clustering in equilibrium: in the voids of the matrix of unclustered big particles, the small particles form subclusters with a sponge-like topology which is accompanied by a characteristic small-wave vector peak in the small-small structure factor. This partial clustering is a general phenomenon occurring for strongly coupled negatively non-additive mixtures.Comment: 12 pages, 5 figures, submitted 200

Lateral Signals in Piezoresponse Force Microscopy at Domain Boundaries of Ferroelectric Crystals

In piezoresponse force microscopy a lateral signal at the domain boundaries is occasionally observed. In recent years, a couple of experiments have been reported and varying explanations for the origin of this lateral signal have been proposed. Additionally, elaborated theoretical modeling for this particular issue has been carried out. Here we present experimental data obtained on different crystallographic cuts of $\rm LiNbO_3$, $\rm BaTiO_3$, and $\rm KTiOPO_4$ single crystals. We could thereby rule out some of the explanations proposed so far, introduce another possible mechanism, and quantitatively compare our results to the existing modeling