Longitudinal RWA samples are unrepresentative self-selected urban professionals

Evidence

These 86 alumni cannot be considered representative of any larger group, not even of my university’s graduates. They went to school for a long time, they allowed the alumni office to keep in touch with them, and they answered my request. Most of them still lived in Winnipeg, and all but 8 still lived in Canada. As a group they are Canadian urban professionals, married with children. — Bob Altemeyer, The Authoritarian Specter, 1125