First Concrete Estimates of Hurricane Maria Displacement

It Ain’t Pretty

In the wake of Hurricane Maria, lots of analysts and observers have attempted to get a handle on how many people will be displaced from Puerto Rico. This is hard to do, because there are lots of different places people can be displaced to, and the numbers of displacees are likely to be large.

Attempts to estimate this have varied widely. Think tanks have tried to make forecasts based on theoretical models of effect sizes. I’ve published different population simulation scenarios. And of course, government agencies have published their own numbers. The state of Florida has been particularly transparent, in a way that is both helpful and deeply unhelpful.

About every week, Florida’s gubernatorial administration issues a press release about Puerto Rico displacees to Florida. It includes interesting figures like, “Since October 3rd, 2017, more than 318,000 individuals have arrived in Florida from Puerto Rico through Miami International Airport, Orlando International Airport and Port Everglades. More than 38,000 individuals have visited the Multi-Agency Resource Centers in Orlando (formerly at Orlando International Airport) and Miami International Airport.”

Now, that might make you think that the displacement from Puerto Rico has been 318,000 individuals to Florida alone.

But that would be very, very wrong. First of all, that’s only gross, one-way traffic from Puerto Rico to Miami, Orlanda, and Port Everglades, so it’s not net movement. Second of all… lots of people fly that route in normal months! I happen to have seen data on how many people fly those route segments in normal months which I am unable to share right now, but the facts are very simple: at least half of that 318,000 figure can be written off to “normal traffic.” Another significant share vanishes when we account for net movement. Finally, keep in mind this data is based on route segments and absolutely not final destination. Of those 318,000, tens of thousands will proceed to board another flight on to some further destination.

That 38,000 number is probably a better estimate of core displacees, as it reflects the number of people who have arrived from Puerto Rico and claimed support as disaster migrants. Somewhere between 38,000 and 100,000 displacees is probably the best estimate for displacees in Florida.

But now, we can do better than that. We finally have October flight data for Puerto Rican airports.

It is ugly.

Here’s monthly domestic departures and arrivals in Puerto Rico:

The first thing to note is that fewer people flew away from Puerto Rico in the post-Maria period than almost any other month in the time series.

The thing you have to remember is that in the wake of the hurricane, airlines scheduled less service, so even if every flight was packed (I’ve seen load data; they were packed), total departures were not exceptionally high. What was exceptional was how low arrivals were. Look at that!

The next thing to note is that arrivals and departures crash in September, which is before Hurricane Maria, corresponding to bad expectations for Hurricane Irma. Furthermore, notice that there is a big drop in every September/October period. The baseline matters.

So let’s smooth this out, and show it on a net basis. Over the preceding 12 months, what have net domestic air passenger balances looked like for Puerto Rico?


OOF. Look at that! Puerto Rico appeared to be recovering in terms of net movements! And then… BAM, Hurricanes Irma and Maria slam through the Caribbean. From November 2016 to October 2017, nearly 180,000 more people have flown from PR to the US mainland than from the US mainland to PR. International balances are delayed by 3 months but we can expect these numbers to get worse once we have that data.

So what we know now is that net displacement in the immediate aftermath Hurricanes Irma and Maria (impossible to separate the two in the time series) is at least 135,000 people. November data and international data will probably blow that number up to 150,000 or more, possibly as high as 200,000.

But here’s the trick. That doesn’t mean the next relevant ACS/PRCS survey will show a loss of 200,000 people. We will eventually get data for December, January, February, March, April… recovery will eventually occur. Many displacees will return home. As of now, the big “known unknown” is what the return rate will be. Future airline data will help elaborate that, and there are other ways of getting at that as well.

But for now, I want to keep this blog post short. We have our first short-run displacement numbers. They are large. The field has been set; now we see how much bounce-back there is in migration to determine what annual numbers will look like.

Check out my Podcast about the history of American migration.

If you like this post and want to see more research like it, I’d love for you to share it on Twitter or Facebook. Or, just as valuable for me, you can click the recommend button at the bottom of the page. Thanks!

Follow me on Twitter to keep up with what I’m writing and reading. Follow my Medium Collection at In a State of Migration if you want updates when I write new posts. And if you’re writing about migration too, feel free to submit a post to the collection!

I’m a native of Wilmore, Kentucky, a graduate of Transylvania University, and also the George Washington University’s Elliott School. My real job is as an economist at USDA’s Foreign Agricultural Service, where I analyze and forecast cotton market conditions. I’m also a Research Fellow at the Institute for Family Studies, a Senior Contributor at The Federalist, and an Advisor at Demographic Intelligence, the nation’s leading producer of rigorous national- and regional birth and marriage forecasts. I’m married to a kickass Kentucky woman named Ruth.

DISCLAIMER: My posts are not endorsed by and do not in any way represent the opinions of the United States government or any branch, department, agency, or division of it. My writing represents exclusively my own opinions. I did not receive any financial support or remuneration from any party for this research.

Like what you read? Give Lyman Stone a round of applause.

From a quick cheer to a standing ovation, clap to show how much you enjoyed this story.