Original sentence: A study by the Minisry of Immigration and Integration in 2018 found, among other findings in the study, that  same-aged children and youth retain a disparity of results depending on immigration status, especially in the case of being a descendant of immigrant, adding a number of possible causes, such as a significantly lower average age for immigrant mothers, which by itself was theorized by the study to be because of increased restrictions to family reunification.The study also concluded, however that "the amount of children that are descendants of immigrants is today so low that it isn't possible to predict the future demographic behavior for this group
Edited sentence: For decades, Danish immigration and integration policy was built upon the assumption that the next generation of immigrants would do better than the previous one and eventually do as well as Danes in education and employment.This assumption was disproven by a 2019 study by the Danish Immigration Service and the Ministry of Education, where the second generation did better than the first generation, but the third generation did no better than the second and in some cases worse