A 23-year Harvard and Columbia University study was recently published shedding new light on the long-term impacts of teachers with both high and low value-added estimates. Researchers Chetty, Friedman, and Rockoff tracked math and reading assessment data on over 2.5 million students from 1989-2009. They then incorporated 90% of these
In a previous post I showed how to implement Stewart's (1980) algorithm for generating random orthogonal matrices in SAS/IML software. By using the algorithm, it is easy to generate a random matrix that contains a specified set of eigenvalues. If D = diag(λ1, ..., λp) is a diagonal matrix and
Because I am writing a new book about simulating data in SAS, I have been doing a lot of reading and research about how to simulate various quantities. Random integers? Check! Random univariate samples? Check! Random multivariate samples? Check! Recently I've been researching how to generate random matrices. I've blogged
