“If it wasn’t for all of these transplants moving into our area, we wouldn’t be dealing with _____!” Sound familiar? Have you heard anyone make this comment about car accidents in Miami? Many people are quick to blame an uptick in people moving to Miami as the cause of a notable increase in car accidents between 2020 and 2021, and while we can certainly draw a parallel between these two data points, is that really what’s going on?
Interestingly enough, a study by the University of Miami found that there was, in fact, a correlation between an increase in new residents moving to Miami and an increase in car accidents. However, they also found that this correlation was not nearly as strong as many people believe it to be. So while new residents may be playing a role in the increase of car accidents, there are likely other factors at play as well.
Understanding Causality and Correlation
Using statistics to draw false causality between two unrelated — or loosely related — data points has long been a go-to trick for news outlets, politicians, and others to support their beliefs with erroneous data.
What Is Causality?
Causality is the relationship between an event (the cause) and a second event (the effect), where the second event is a direct result of the first. In other words, causality is when one thing can be directly attributed to another.
For example, you are likely familiar with the saying “correlation does not imply causation.” Just because two data points are related does not mean that one caused the other. This is an important distinction to make because it’s all too easy to draw false causality between unrelated data sets.
What Is Correlation?
Correlation is simply when two data sets are related. This relationship can be positive (meaning they move in the same direction), negative (meaning they move in opposite directions), or there may be no relationship at all.
When it comes to car accidents, we can see that there is a correlation between the number of new residents moving to Miami and the number of car accidents. However, correlation does not imply causation, so we cannot say for certain that the increase in new residents is causing the increase in car accidents.
Does Eating a Lot of Chocolate Improve Your Chances of Winning a Nobel?
In fact, did you know that there is a direct correlation between chocolate consumption in a country and the number of Nobel laureates from the chocolate-loving nation? It’s true! However, this does not mean that eating chocolate will improve your chances of winning a Nobel because this study does not work on an individual level, only on a population level.
Researchers have further determined that a country’s Gross Domestic Product (GDP), a key indicator of wealth, is also closely correlated with both chocolate consumption (and other luxury foods) and Nobel laureates — simply put, a country that can afford to eat chocolate in large volumes also has the money to produce internationally-renowned scientific research.
This just highlights the simplicity of drawing causality when there is none.
Is Population Growth Causing an Increase in Car Accidents?
Between 2020 and 2021, there was a population increase of 1.18% in Miami-Dade County. In 2020, there was a total of 51,543 accidents reported in Miami, and in 2021 there was a shocking 21% increase to 62,520 crashes. Do these numbers sound closely tied?
Source: https://www.usapopulation.org/miami-population/
With more residents and more cars on the road, it stands to reason that there would be more car accidents. In fact, when controlling for other factors, a study found that an increase in vehicle registration was a significant predictor of an increase in car accidents.
What role did COVID-19 play in this change, though? If we look back to the 2019 car accident data and compare it to 2021, there was only a change of 4 percent… a 4.02% DECREASE!
What Other Factors Are Contributing to the Increase in Car Accidents?
The study also found that other factors, such as an increase in distracted driving (due to the use of cell phones and other devices), played a role in the increase in car accidents.
Of course, there are many other potential factors that could be contributing to the increase in car accidents, such as the number of new residents who are unfamiliar with the roads, an increase in traffic congestion, or even adverse weather conditions.
Wait a Minute, Has There Really Been an Increase in Car Accidents?
So far we’ve found that there was, in fact, a 21% increase in car accidents between 2020 and 2021, but that there was a 4% decrease in accidents between 2019 and 2021. As you can see in the charts below, there was a drastic reduction in accidents starting in February 2020 and lasting until about August, when accidents returned to numbers that were similar to pre-Covid statistics.
Car Accidents in Miami-Dade in 2019
Car Accidents in Miami-Dade in 2020
Car Accidents in Miami-Dade in 2021
What differences do you see in these three graphs? Is there anything that could have caused a decrease in road traffic — and therefore accidents — at the beginning of 2020?
The Bottom Line
So, while we cannot say for certain that the surge of new residents in Miami is causing more car accidents, we can say that there is a correlation between the two. However, we can clearly see that there is also a major disruption at the beginning of 2020 that impacted the number of vehicles on the road and therefore caused a significant decrease in accidents.
So whether you are a recent addition to Miami’s population or just like being fun at parties, break out these graphs next time you hear someone complaining about all of “these out-of-staters moving to Miami causing more car accidents,” just break out these graphs and let the data do the talking!
The dirty secret is that Miami drivers have ALWAYS caused lots of accidents and probably always will. If you or a loved one are in an accident in Miami, the best thing you can do after getting the appropriate medical care is hire an attorney. 1-800-Injured is an attorney and medical referral service. Contact us now to connect with a car accident lawyer who can help you fight for the compensation you deserve — no matter if your accident was caused by a lifelong Miami resident, a new transplant, or a confused tourist.