Our thanks to the reader who asked, “It is well known that driving your car is more dangerous than flying in an airplane, and I am sure there are statistics to back that up. Can you compare the statistical risk of driving in a car compared to flying in a plane compared to being in a school during a school shooting?”
To answer this serious question with applied math calculations, we must first decide what statistics to compare and how to compare them. Another important task is finding reliable and relevant data.
What Statistics Will We Compare?
Our reader asked us to compare the risks of “driving a car,” “flying in a plane” and “being in a school during a shooting.” Taken literally, the first risk is whether one would get into a car and drive it. “Flying in a plane” includes being a passenger or pilot. However, the key phrase is “during a school shooting.”
Therefore let’s assume the intent is, “What is the risk of being in a car or airplane during a crash, compared to being in a school during a shooting.”
Let’s note that “What is the risk of injury or death, given that one is already in an automobile collision, an airplane crash, or a school shooting” is a completely different question.
Statistics for School Safety and Aviation Safety
Let’s focus on a one year period of fairly recent data for the United States, and include students, educators and support staff as the “population” in the schools, since anyone may become a shooting victim. Let’s include elementary, secondary and collegiate institutions on historic grounds. My aviation safety source does not make it obvious that both passengers and crew are included in the fatality reckoning.
On Dec. 12, 2013, Brandy Zadrozny’s article, The School Shootings You Didn’t Hear About: One Every Two Weeks Since Newtown, reported that there had been 24 shooting incidents, 24 injuries and 17 deaths in United States schools during school hours in the past year. (One day later came another shooting, in Colorado, in which 2 were injured and the shooter died).
To determine the rate of shooting incidents, we need the number of institutions. Two tables from the USA’s National Center for Education Statistics provide details. Projected number of participants in educational institutions, by level and control of institution: Fall 2012 states that the total of enrollment, faculty and support staff at all levels totals 86.7 million people. Number of educational institutions, by level and control of institution: Selected years, 1980-81 through 2010-11 claims 138,925 educational institutions in the 2009-2010 school year. (They seem to take the census every two years).
Since the aviation safety statistics deal with “incidents and accidents” per flight, and with rates “per 100,000 flight hours”, we must develop an equivalent statistic for school safety. Let’s estimate the number of days and hours that an average school might be open for classes during a year.
School Shooting Statistics Summary
Here are the facts and estimates regarding school shootings in the USA, for all American educational institutions:
- 138,925 educational institutions, including elementary schools, high schools and colleges.
- 131.25 estimated average number of days that these educational institutions are open, with students in classes.
- 18,233,906 estimated total number of Institution-Days.
- 6 estimated average hours that an institution has students in classes.
- 109,403,438 estimated total number of Institution-Hours.
- 24 shooting incidents during the 365 day period of Zadrozny’s study.
- 0.02 estimated shooting incidents across all educational institutions per 100,000 Institution-Hours.
The number of schools is well based. The days and hours may be on the low side; if higher, then the incident rate would be even lower. Other years may have higher numbers of incidents. We ignored the number of victims per incident. However, as the spreadsheet shows, the rates of death and injury were even smaller than the rate per Institution-Hour.
Aviation Incident and Accident Summary
The National Business Aviation Association (NBAA) reports accident rates per 100,000 flight hours. In 2012, Safety Statistics reported a total incident and accident rate of 6.44 for general aviation. The rate of fatal occurrences was 1.17.
Apparently this is the rate for the hours that airplanes were flying, rather than passenger-hours.
Comparing School Shooting Rates versus Airplane Safety
We estimate that the rate of school shootings is approximately 0.02 per 100,000 hours that educational institutions hold classes.
The aviation industry report shows a rate of over 6 occurrences per 100,000 flight-hours. These include skids on runways, not simple “plane crashes.”
The conclusion is that an airplane flight may be 300 times more likely to experience an accident or incident, compared to the same time spent in a classroom session in an educational institution in the United States.
Similar research might compare, for example, the relative likelihood of escaping injury given that one is in an airplane crash versus in a school during a shooting incident. The key is to define the question and find relevant statistics.
Note: Automobile crash rates vary widely by age of driver, time of day, and a number of other variables. One may also speculate whether any published accident rates ignore minor fender benders that might not be reported. For this reason, we’ve left car crash statistics out of this statistical evaluation.
Decoding Science. One article at a time.