More than a decade of uninterrupted growth in New Orleans' population that accompanied the recovery from Hurricane Katrina has ended, according to new U.S. Census Bureau estimates.

New Orleans saw its population shrink by nearly 1,000 people between 2016 and 2018, the first decline the city has seen since tens of thousands of displaced residents began returning after the storm, according to census figures.

The drop may mirror a nationwide trend that has seen residents leaving core cities, in part because of the high cost of housing and other necessities, for smaller and cheaper areas, demographers said. And it may also point to weaknesses in the economy of New Orleans and of Louisiana as a whole, which lost 10,840 residents over the course of a year.

New Orleans had just over 391,000 residents in 2018, about 80.7 percent of its pre-Katrina population, according to estimates being released on Thursday. That’s about 530 fewer than the year before and more than 970 fewer than in 2016.

Those losses are relatively small, but they come after a decade of often rapid growth as residents returned and rebuilt their flooded and storm-damaged homes. They suggest that New Orleans may be returning to the overall downward trajectory it had shown since its population peaked in the 1960s.

Up until about 2015, New Orleans saw growth in all three categories used by the Census Bureau for its estimates: a natural increase from births and both domestic and international migration, said Luke Rogers, chief of the bureau's Population Estimates Branch.

But “in the last three years or so, the natural increase has slowed, the net international migration has slowed a little bit, and the domestic migration has gone net negative,” Rogers said.

The population also ticked downward for the New Orleans metropolitan area as a whole. The eight parishes the Census Bureau considers as part of that region collectively lost 66 people over the course of a year.

The bureau's official definition of the metropolitan area includes Orleans, Jefferson, St. Tammany, Plaquemines, St. Bernard, St. Charles, St. John the Baptist and St. James parishes.

Regional officials tend to exclude St. James when they consider the New Orleans metro area. Using their seven-parish definition, the population actually increased by about 220 people.

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Jefferson Parish saw a decline of almost 2,250 people in 2018, about half a percentage point of its population, after losing about 450 people the year before. The parish remains the largest in the metro area, though, with about 434,050 people.

On the other side of the ledger, St. Tammany continued the steady growth it has seen for nearly two decades, adding about 2,290 people in 2018 to reach a population of about 258,100.

Statewide, Louisiana's population shrank by 10,840, or about a quarter of a percentage point.

But more troubling than the overall statewide decline is how much of it was driven by people choosing to leave the state, said Robert Eisenstadt, an economics professor and director of the Center for Business and Economic Research at the University of Louisiana at Monroe.

About 27,000 more people chose to move out of the state than into it, a number that was somewhat offset by the fact that more people were born than died.

“In Louisiana we have a fundamental problem attracting the businesses and the industries that are attractive to populations that are more likely to migrate,” Eisenstadt said.

“When you look at 27,000 people leaving the state, that’s got to be a work-related consequence,” he said.

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Similarly, New Orleans saw more people leave than move in. About 1,900 more New Orleanians packed up and moved elsewhere in the U.S. in 2018 than the city was able to attract from other locations.

Allison Plyer, the chief demographer for the Data Center in New Orleans, did not have access to the Census Bureau estimates before their public release. But she said previous census estimates, which showed population growth slowing in recent years, were potentially a troubling sign for a city that has few major industries outside of tourism.

The population decline comes amid a loss in jobs in industries such as oil and gas, the depletion of federal funds that paid for the post-Katrina recovery, and uncertainty about what new industries can be attracted to the city.

“It's 14 years after Katrina and several years into a number of economic development policies like trying to develop a digital economy, and the population trends are not positive,” Plyer said. “We might need to take a harder look at our strategies for growing the economy and diversifying it.”

The population losses also come as the city is facing an affordable housing crisis that has priced out some people unable to find houses or apartments they can afford. Larger and more expensive cities that have faced their own problems with affordable housing, such as New York City and Los Angeles, have also been seeing people leave in recent years, said William Frey, a demographer and senior fellow at the Brookings Institution.

The Census Bureau population estimates are based on federal records, such as tax returns, that track where people are living, as well as data on birth and death rates. That leaves some room for error, something demonstrated in part with revisions the bureau made to its previous estimates when it released the new numbers this week.

Last year, the bureau's estimates showed the city’s population leveling out but still increasing slightly in 2017. The agency now believes the city actually lost people that year.

Independent of that decline, the Census Bureau also revised its estimates of New Orleans' overall population in recent years, cutting the figures it had previously put out for the years since 2010. The total for 2017 fell by about 1,750. The estimates of annual population loss are based on those new numbers.

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The most accurate figures won’t be available until after the next full national headcount in 2020, Plyer said.

“The 2020 count is going to be the real litmus test, and it relies on everyone being willing to stand up and be counted,” she said. “It drives representation (in Congress) and more than $800 billion in federal funding over the next 10 years.”