Professor Putnam's research on diversity is having an effect. In the past few days there's been another round of discussion on his research, with some former supporters of open borders now having second thoughts.
I've already written a number of posts on Putnam, so rather than repeating myself I'll just give the following links:
Professor Putnam: hunkering after diversity
This post presents Professor Putnam's research results which show that diversity encourages social withdrawal. A higher level of diversity decreases solidarity, happiness, friendship and trust.
What really drives Putnam?
Here I look at the arguments put forward by Professor Putnam for continuing to embrace diversity despite its negative effects on social capital.
Professor Putnam's challenge
Professor Putnam ends his research paper with a (convoluted) attempt to explain how diversity might be maintained without the damage to social capital.