Overtime can be beneficial for both employees and companies. It provides the company with the flexibility to cover unexpected absences and changes in demand without hiring more staff and it gives employees extra income at a premium rate.
However, overtime has its downsides too. While many employees will happily take as much overtime as is available, there is growing scientific evidence that relying too much on overtime can lead to numerous problems for an operation.
Below are five consequences to relying on excessive amounts of overtime:
#1 - Increased Health Problems
A considerable body of scientific work has explored the health problems associated with working excessive overtime. Some health problems that have been linked to long working hours include: 7-11
• Lower-back injury in jobs with a lot of manual lifting
• Higher blood pressure among white-collar workers
• Increased mental health issues
• Increase in total and lost workday injury rates
• Lower birth weight or gestational age in women
• Heavy alcohol consumption among men
• Higher suicide rates
A study by Cornell University shows that approximately 10% of employees who work 50 to 60 hours per week report severe work-family conflicts.12 This number jumps to 30% for those who work more than 60 hours. The divorce rate also increases as weekly hours increase. These factors contribute in turn to mental health and alcohol problems.
A Canadian study showed that workers who increased their work hours from 40 hours or less per week to over 40 hours per week experienced an increase in tobacco and alcohol consumption, an unhealthy weight increase among men, and an increase in depression among women. 13
These health problems contribute to the indirect costs of allowing excessive overtime to occur. Health care costs, absenteeism, and turnover will increase, while productivity will decrease.
#2 - Increased Safety Risk
Long work hours have been linked to increased safety risk in several studies (reviewed by
Rosa), including: 11
Safety and performance at nuclear plants
Impaired performance and lowered attention
An increase in errors in medical facilities
A threefold increase in accident rates after 16 hours of work
These additional safety problems are likely due to worker fatigue, which could be from a single long day or from the cumulative effect of multiple days of long hours. A German study showed that doctors who worked over 48 hours a week were five times more likely to have a driving accident (either while traveling to a call, or while commuting). 14
While working at night and during the early morning has been linked to an increased risk of transportation accidents, research also suggests that long work hours in themselves contribute to accident rates.15 As they become more fatigued, drivers become less cautious, execute more dangerous maneuvers, and exhibit more erratic driving patterns.
Circadian data from shift work operations (not just transportation operations) shows that companies with more fatigue-related problems are also likely to have higher rates of overtime (Figure 6), emphasizing the effect that longer work hours can have on sleep quantity and quality.