The past few years have seen a marked decline in the number of people migrating from the U.S. to Mexico, according to a new Pew Research Center report.

Why it matters: Mexico has long been the largest country of origin for immigrants in the U.S. However, there was even more migration from the U.S. to Mexico in the 2000s and early 2010s— a trend that reversed in the years before the pandemic.

• It's not that there was a big spike in Mexicans migrating to the U.S. during that time. Rather, far fewer people have been returning to Mexico, according to Pew.

By the numbers: Roughly 690,000 people in the U.S. moved to Mexico between 2013 and 2018, according to Pew — down from 1 million people who made that move over the previous five years.

Between the lines: Job losses from the 2008 financial crisis, stricter U.S. immigration enforcement and slowing birth rates in Mexico all may have contributed to more people going to Mexico than the U.S. during the 2000s and early 2010s, according to Pew researchers.

• The Mexican economy has also been more stable in recent decades compared to the 1980s and 1990s, when Mexican migration to the U.S. was at its peak. After spiking in the '80s and '90s, the number of Mexican immigrants in the U.S. has slowly declined since 2007.

What to watch: The pandemic's impact on migration between the U.S. and Mexico still isn't fully clear.

• But, Pew notes, the number of green cards and high-skilled visas given to Mexicans dropped significantly in 2020, compared to the year before. And there was much slower growth in the number of Mexicans who received short-term farmworker visas.
• And while this study covers broad trends over a five-year period, the number of border crossings by Mexicans into the U.S. has surged over the past several months.
• With just eight months of data reported, border patrol has made more arrests of Mexican migrants than in any full fiscal year since 2009, according to Customs and Border Protection data.

Yes, but: The vast majority of Mexican families and adults arrested at the border have been kicked back to Mexico under a Trump-era public health order kept in place by President Biden. The policy has likely contributed to the increased number of migrants making multiple attempts to cross the border.