This topic and the related studies noted were discussed recently by Carl Benjamin on the podcast of the lotus eaters. The leftists push for diversity but refuse to acknowledge the harm they are doing to the society that has been 'enriched' with diverse cultures and ethnicities. People don't hold the same historical value to an area and don't respect eachother as they once did, people litter and commit crimes, segregate until the original community is gone and all you have left is an Islamic ghetto selling khat from a dodgy kebab house near a mosque where a library and a post office used to be. Diversity is weakness, and we are being colonised by invaders who intend to relocate the people from their homes.