Background

On Sunday, March 10, 2024, most of the United States will spring forward an hour and enter Daylight Saving Time (DST). Over the last decade, the debate around whether to get rid of DST has intensified. This time change has recently prompted intense discussion regarding its impacts and future in the United States. In fact, Marco Rubio, a Senator from the state of Florida, reintroduced a bill just last year aiming to make daylight saving time permanent. On the other side, some people are pushing to keep the status quo and others are looking to make Standard Time the norm year round.

In 2013, Chmura Economics & Analytics completed a study examining the economic costs of DST. We have now updated that study with information from the most recent academic research and cost drivers. Like the previous study, we focused only on aspects of economic loss where evidence from peer-reviewed journals could be obtained. These studies provided evidence that the DST change led to an increase in heart attacks (myocardial infarctions), strokes, workplaces injuries (in specific industries^[1]), and traffic accidents. Importantly, these impacts only happened with the Spring change (when we lose an hour of sleep) and not during the Fall change. This makes sense, given the issue here is not the time change itself, but the sleep loss that comes as a result.

Based on these increases, we were able to calculate the economic cost of DST for each metropolitan statistical area (MSA) in the United States. Our economic cost estimates not only included the direct cost of an injury or accident, but also the indirect cost associated with an incident including lost wages/productivity due to injury. In unfortunate circumstances when loss of life occurred due to heart attack, stroke, workplace injuries or traffic accidents, we also considered the costs of increased fatalities using an official “Value of a Statistical Life” (VSL) estimate.^[2] Additionally, there are other impacts of economic loss, such as costs incurred by airline companies, that we do not consider in this analysis.

For a more detailed description of our estimation process and results, interested readers can download a table of the full results and learn more about our methodology below.

Results

Using four categories of cost (heart attacks, strokes, workplace accidents, and traffic accidents), we estimated the total economic cost of daylight saving time for all the MSAs in the United States was approximately $672.02 million annually.^[3] This includes $374.75 million from increased heart attacks, $251.53 million from increases in strokes, $18.35 million from additional workplace injuries, and $27.39 million from increases in traffic accidents. The map and table below display the cost for each MSA ranked by Per Capita Cost.

The results show that Texarkana, Texas-Arkansas will likely have the highest per capita cost from DST at $7.76 from the 386 metro areas in the nation. It is followed by Joplin, Missouri-Kansas and Fayetteville-Springdale-Rogers, Arkansas.

By comparison, the New York-Newark-Jersey City, NY-NJ MSA is ranked 330 at $1.91 which is below the national average of $2.73 for all MSAs. Los Angeles-Long Beach-Anaheim, CA is ranked 268 and Chicago-Naperville-Elgin, IL-IN is 147 at $2.62. Despite being ranked relatively low in per capita cost, these three MSAs have the largest total cost from DST due to their large populations.

MSAs with the lowest per-capita costs include Bozeman, Montana ($1.12), Rochester, Minnesota ($1.37), and Iowa City, Iowa ($1.46). We did not include MSAs in the state of Arizona and Hawaii in our rankings because both states do not observe Daylight Saving Time in their metropolitan statistical areas.

Appendix – Methodology

Compared to the previous study, we have expanded our impacts to include workplace injuries in more industries (NAICS 11, 21, 22, 23, 31, and 48), increased stroke incidence, and increased occurrence of traffic accidents. We also removed the impact of increased "cyberloafing" from our analysis, in part, due to the significant changes that have occurred in the way Americans work over the last decade. In particular, the COVID-19 pandemic dramatically altered America's office culture and we could not identify any post-pandemic studies regarding this relationship.

This economic cost analysis is just an estimate of the negative impacts of Daylight Saving Time and therefore has a sizeable margin of error. Unfortunately, data availability is different for all these metrics and not always available at the MSA level. Therefore, in some instances we had to impute MSA costs by using state or national rate averages (e.g., state-level non-fatal workforce injuries) and applying those to the MSA population or employment totals. See below for further information on methodology for the four cost categories.

For our VSL estimate (used for the cost of increased fatalities), we used the “low” estimate from the United States Department of Health and Human Services (HHS) to be conservative.^[4] There are several different VSL estimates used by different departments of the federal government. However, given that two of our cost metrics are health-related, we only used VSL estimates from the HHS for consistency. Applying a VSL estimate to our model has a higher impact on the costs of heart attacks and strokes given these carry higher mortality rates than workplace injuries and traffic accidents.

Heart Attacks

Heart attacks by MSA are provided by the BRFSS survey and report the percentage of individuals that have ever had a heart attack. We took a 5-year average of this percentage from 2017 – 2021 for each MSA. When the survey did not contain data for an MSA, we substituted the state’s value for that MSA from the survey. After using this percentage to calculate the number of heart attacks that had ever occurred in each MSA, we applied an adjustment factor to each MSA to ensure our estimates were consistent with the total number of heart attacks that occur annually in the nation as reported by the CDC.^[5] To calculate the number of fatal heart attacks we used a similar process but used data from the CDC’s National Vital Statistics System to calculate the fatality rate by MSA.^[6]

Based on a result from a previous study, we assumed that the rate of heart attack increased by 5.1% during the first week after Spring DST for all MSAs.^[7] When applying the cost factor to these additional heart attacks, we consider both the direct medical cost of a heart attack and the indirect cost of lost productivity due to time away from work. The direct medical cost of a non-fatal heart attack was estimated to be $59,158 and included medical costs from the initial heart attack and subsequent related medical expenses a year following the heart attack.^[8] To estimate the indirect costs, we used a study to determine that an average of 36 workdays were lost the year following a heart attack after the patient was discharged from a hospital.^[9] Using this figure, and an estimate of productivity per worker from JobsEQ by Chmura Economics & Analytics, we were able to estimate the indirect cost of lost productivity due to time away from work. We also applied our VSL estimate to the estimated increased mortality.

Strokes

Strokes by MSA are provided by the BRFSS survey and report the percentage of individuals that have ever had a stroke. We took a 5-year average of this percentage from 2017 – 2021 for each MSA. When the survey did not contain data for an MSA, we substituted the state’s value for that MSA from the survey. After using this percentage to calculate the number of strokes that had ever occurred in each MSA, we applied an adjustment factor to each MSA to ensure our estimates were consistent with the total number of strokes that occur annually in the United States as reported by the CDC.^[10] To calculate the number of fatal strokes we used a similar process but used data from the CDC’s National Vital Statistics System to calculate the fatality rate by MSA.^[11]

Based on a result from a previous study, we assumed that the rate of stroke increases by 8% the first two days after Spring DST for all MSAs.^[12] When applying the cost factor to these additional strokes, we consider both the direct medical cost of a stroke and the indirect cost of lost productivity due to time away from work. The direct medical cost of a non-fatal stroke was estimated to be $49,207 and included both medical costs from the initial stroke and subsequent related medical expenses.^[13] To estimate the indirect costs, we used a study to determine that an average of 31.5 workdays were lost the year following a stroke after the patient was discharged from a hospital.[3] Using this figure and an estimate of productivity per worker from JobsEQ® by Chmura Economics & Analytics, we were able to estimate the indirect cost of lost productivity due to time away from work. We also applied our VSL estimate to the estimated increased mortality.

Workplace Injuries

Fatal injury data was last provided by MSA in 2018, some cleaning was performed to update MSA definitions.^[15] For non-fatal injuries, we used national average incidence rates by industry provided by the Survey of Occupational Injuries and Illnesses Data.^[16]These incidence rates were then applied to employment by industry within each MSA. A study from 2009 showed a statistically significant increase in workplace injuries in the mining industry following the DST change.^[17] We reasonably assumed that this increase could apply to other jobs involving physical activity in the following industries: Agriculture, Forestry, Fishing and Hunting; Mining, Quarrying, and Oil and Gas Extraction; Utilities; Construction; Manufacturing; and Transportation and Warehousing.

For the cost of non-fatal workplace injuries, we used the average compensation rate for injured workers from the National Council on Compensation Insurance’s Workers Compensation Statistical Plan database.^[18] This is then increased to account for indirect costs not covered by compensation insurance such as recovery of lost production, administrative time spent by HR, OSHA fines, and so on. Fatal injury costs are represented by VSL in the model.

Traffic Accidents

Fatal traffic accidents are provided by county and matched to MSA (averaging data in the month of March from 2017-2021). Some cleaning was required to account for recent MSA changes. Proportional estimates were then extrapolated for non-fatal accidents by multiplying the fatal incidence rate in an MSA by the increased likelihood of injury only and property damage only accidents (based on national rates). These data are sourced from the National Highway Traffic Safety Administration.^[19]

Based on a recent study looking into the effects of DST on traffic accident risk, we assumed traffic accidents increase by 6% the day following the DST switch.^[20] To estimate the costs of traffic accidents, non-fatal cost data are based on average insurance claim amounts.^[21] “Evident” injury average economic costs were used for injury only accidents and “Property damage only” costs were used to estimate economic costs for property damage only accidents. VSL is applied for fatal accident cost.

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 [1]  These industries include Agriculture, Forestry, Fishing and Hunting; Mining, Quarrying, and Oil and Gas Extraction; Utilities; Construction; Manufacturing; and Transportation and Warehousing

[2]  “Value of a Statistical Life is a common method of assigning a price to fatalities. This metric is used by many United States federal government agencies in official cost-benefit analyses. Other cost estimates from fatalities (such a present value of remaining wages) are typically smaller than VSL.

[3]  All MSAs does not include the entire United States. Total national costs would likely be marginally higher as about 12-14% of the United States population lives outside an MSA.

[4] Source: Appendix D: Updating Value per Statistical Life (VSL) Estimates for Inflation and Changes in Real Income

[5]  Source: 2024 Heart Disease and Stroke Statistics: A Report of US and Global Data from the American Heart Association

[6]  Source: Interactive Atlas of Heart Disease and Stroke

[7]  Source: Daylight Saving Time and Acute Myocardial Infarction: A Meta-Analysis

[8]  Source: Patient-level costs of major cardiovascular conditions: a review of the international literature

[9]  Source: Productivity loss and indirect costs associated with cardiovascular events and related clinical procedures

[10]  Source: Centers for Disease Control and Prevention, Stroke Facts

[11]  Source: Interactive Atlas of Heart Disease and Stroke

[12]  Source: Changes in ischemic stroke occurrence following daylight saving time transitions

[13] Source: 2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

[14]  Source: Productivity loss and indirect costs associated with cardiovascular events and related clinical procedures

[15] Source: Census of Fatal Occupational Injuries ‐ Archived Data

[16] Source: Survey of Occupational Injuries and Illnesses Data, Table SNRO5. Injury cases - rates, counts, and percent relative standard errors - detailed industry, Accessed March 2024

[17]  Source: Journal of Applied Psychology 2009, Vol. 94, No. 5, 1305–1317 Changing to Daylight Saving Time Cuts into Sleep and Increases Workplace Injuries Christopher M. Barnes and David T. Wagner, Michigan State University

[18]  Source: The Real Cost of a Workplace Injury

[19] Source: National Highway Traffic Safety Administration, Fatality and Injury Reporting System Tool (FIRST)

[20]  Source: A Chronobiological Evaluation of the Acute Effects of Daylight Saving Time on Traffic Accident Risk

[21]  Source: Costs of Motor-Vehicle Injuries