THE MILLIONS OF AMERICANS WHO DO NOT GET ENOUGH SLEEP NIGHT AFTER NIGHT RISK DEVELOPING CUMULATIVE NEUROBEHAVIORAL DEFICITS and experiencing sleepiness-related errors and accidents.1–3 Since reduced sleep duration has frequently been associated with a higher prevalence of obesity,4 morbidity, and mortality,5 these people may also be incurring health risks, although it remains uncertain whether these relationships are causal. In this issue of SLEEP, Knutson and colleagues6 attempt to address the question of whether sleep duration among Americans has been steadily decreasing, using time use studies. Although many who believe Americans are sleeping less each decade attribute this to a culture that increasingly perceives sleep as a flexible commodity that can be exchanged for waking activities considered more essential or of greater value,7 the investigation of secular trends in the prevalence of sleep duration is complicated by inconsistent methodologies for establishing sleep time using surveys. This is what makes the study of Knutson et al.,6 which focuses on 8 nationally representative time use studies performed between 1975 and 2006, unique and important. Looking . . .