too difficult. Underload: Having work that fails to use a worker's skills and abilities. Workload as a work demand is a major component of the demand-control model of stress. This model suggests that jobs with high demands can be stressful, especially when the individual has low control over the job. In other words, control serves as a buffer or protective factor when demands or workload is high. This model was expanded into the demand-control-support model that suggests that the combination of high control and high social support at work buffers the effects of high demands. As a work demand, workload is also relevant to the job demands-resources model of stress that suggests that jobs are stressful when demands (e.g., workload) exceed the individual's resources to deal with them. Long hours According to the U.S. Bureau of Labor Statistics in 2018, approximately 13,060,000 Americans or 8.7% of the labor force worked 41–48 hours per week. Approximately 14,734,000 Americans or 9.8% of the labor force worked 49–59 hours per week. And approximately 9,877,000 Americans or 6.7% of the labor force worked 60 or more hours per week. A meta-analysis involving more than 600,000 individuals and 25 studies indicated that, controlling for confounding factors, working long hours is related to a small but significantly higher risk of cardiovascular disease and slightly higher risk of stroke. Status A person's status in the workplace is related to occupational stress because jobs associated with lower socioeconomic status (SES) typically provide workers less control and greater insecurity than higher-SES jobs. Lower levels of job control and greater job insecurity are related to reduced mental and physical health. Salary The types of jobs that pay workers higher salaries tend to provide them with greater job-related autonomy. As indicated above, job-related autonomy is associated with better health. A problem in research on occupational stress is how to "unconfound" the relationship between stressful working conditions, such as low levels of autonomy, and salary. Because higher levels of income buy resources (e.g., better insurance, higher quality food) that help to improve or maintain health, researchers need to better specify the extent to which differences in working conditions and differences in pay affect health. Workplace bullying Workplace bullying involves the chronic mistreatment of a worker by one or more other workers or managers. Bullying involves a power imbalance in which the target has less power in the unit or the organization than