Producers of infant formula employ comprehensive food safety systems, including product testing to ensure those systems are working. A new study from the University of Illinois Urbana-Champaign finds ...

Many data sets used by economists and other social scientists are collected by stratified sampling. The sampling scheme used to collect the data induces a probability distribution on the observed ...

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

It is shown that variance estimates for regression coefficients in exposure-stratified case-cohort studies (Borgan et al 9 Lifetime Data Anal., 6,2000,39-58) can easily be obtained from influence ...