[kelukelugames]

Here's the abstract from your link. A bit more complicated than your summary.

Ethnic diversity is increasing in most advanced countries, driven mostly by sharp increases in immigration. In the long run immigration and diversity are likely to have important cultural, economic, fiscal, and developmental benefits. In the short run, however, immigration and ethnic diversity tend to reduce social solidarity and social capital. New evidence from the US suggests that in ethnically diverse neighbourhoods residents of all races tend to ‘hunker down’. Trust (even of one's own race) is lower, altruism and community cooperation rarer, friends fewer. In the long run, however, successful immigrant societies have overcome such fragmentation by creating new, cross-cutting forms of social solidarity and more encompassing identities. Illustrations of becoming comfortable with diversity are drawn from the US military, religious institutions, and earlier waves of American immigration.

[yummyfajitas]

If you read the paper itself, it's basically empirical work describing the negative effects, followed by an essay claiming the positive ones. As I said - he spent 6 years looking for something to counter his empirical results, and published when he came up with it.

Note also that I'm not strongly endorsing this work - I'm just pointing out the strong desire to not publish a result against diversity.

[kelukelugames]

Thanks for explaining. I guess people are still wary since The Bell Curve.