WARSAW, Poland (AP) — Poland is losing large numbers of Ukrainian refugees from its workforce as they travel to Germany to seek higher wages and government benefits in the rich Western economy, according to a report published Tuesday.

Although the refugees are not economic migrants, they are increasingly taking on work as the war in Ukraine drags on for more than a year and a half.

Where they choose to live impacts labor markets in European nations, which are desperate for workers and are facing demographic declines due to low birthrates.

Poland is not their first choice anymore, said Michalina Sielewicz, director of economic development for EWL, an employment agency that carried out the research along with the Center for East European Studies at the University of Warsaw.

“We should be worried,” she said.

The study sought to understand why the number of Ukrainian refugees has been decreasing in Poland, a first stop for many after Russia’s invasion of Ukraine on Feb. 24, 2022, and why the number has been growing in Germany. For the first months of the war, Poland hosted more Ukrainian refugees than any other country.

That has changed. According to European Union statistics, there were 1.1 million Ukrainian citizens registered in Germany at the end of June, compared to 975,000 in Poland. That amounts to a decrease of more than 350,000 in Poland since August 2022, while the number has grown more than 410,000 in Germany.

Of the 350,000 who left Poland, 150,000 went to Germany, according to the report, titled “From Poland to Germany. New Trends in Ukrainian Refugee Migration.”

The study found that a developing network of Ukrainians in Germany is a factor in the migration shift, as people already established there help friends and acquaintances make the step. The Ukrainians questioned in the study also gave other reasons for choosing Germany, including higher wages, higher social benefits for refugees and better medical services.

The study also pointed to German language classes organized by the government for refugees as an important factor that has helped Ukrainians become integrated into society and find their way in the workforce. The Polish government, by contrast, does not offer free language training to refugees.

The study interviewed 400 Ukrainian refugees who had first fled to Poland and then moved to Germany.

Jan Malicki, director of the Center for East European studies, said 400 was a large enough group to draw conclusions. But he cautioned that the biggest unknown now is how many people will want to return to Ukraine after the war, something that will be determined by the extent of the destruction and what conditions the Ukrainian state will be able to offer them.