Kelly [22] conducted a study: Who sleeps better?
Socioeconomic differences in reports of sleep disturbance.
Results indicate that individuals with higher socioeconomic
status and education levels sleep better than those of lower
socioeconomic status. Findings show that 26% of individuals
earning less than $10,000 a year reported sleep problems,
whereas only 8% of those earning $75,000 or more annually
reported sleep problems.