We’ve reported previously on Putnam’s diversity research on the impact of diversity on social capital (social ties between group and within groups).
John Leo’s article in the City Journal is completely inaccurate on one important point, that political correctness kept us from releasing these results and the data. We never held back on releasing our findings.
In fact, within weeks of getting the original survey results in early 2001 (six years ago) we issued a national press release describing our preliminary findings in detail. That press release was covered at the time in many publications, including the LA Times, the Atlanta Journal Constitution, the San Francisco Chronicle, the Minneapolis Star-Tribune, and so on, often quoting me specifically about the diversity-distrust connection. The SF Chronicle of March 1, 2001, for example, quoted Putnam as follows: “Places that are ethnically diverse and that have large numbers of recent immigrants are places that have greater challenges in building connections because people feel more isolated there,” Putnam said. “And that’s not just along racial lines, [but] generalized social isolation.”
And a few months later in 2001 (just as soon as the data had been cleaned) we made the full, raw data-set publicly available to anyone through the Roper Center data archive. Over the last six years, those data have become one of the most widely-used data-sets in the social sciences, downloaded and analyzed by hundreds of other researchers.
Finally, contrary to Leo’s claim, we have not “published only an initial summary” of our findings, but an elaborate 38-page journal article, packed with charts, statistics and methodological details, and as we have said, the raw original data have been publicly available for six years, an invitation to early scrutiny that is almost unprecedented in social science. In short, our story is the exact opposite of suppressing results which is why Leo’s story is so galling, regardless of whether Leo likes the findings or not.
Social Capital Blog 
Dr. Putnam certainly did publicize his findings for a time in 2001, at which time I wrote about them.
He is being disingenuous, however, because he is skipping over the subsequent half decade of virtual radio silence he maintained on the topic from 2001 until he gave an indiscreet interview, which he immediately regretted, to John Lloyd of the Financial Times in the fall of 2006 while making a presentation on his findings in Sweden. Lloyd wrote:
“This is a contentious finding in the current climate of concern about the benefits of immigration. Professor Putnam told the Financial Times he had delayed publishing his research until he could develop proposals to compensate for the negative effects of diversity, saying it “would have been irresponsible to publish without that”.”
http://www.ft.com/cms/s/c4ac4a74-570f-11db-9110-0000779e2340.html
Putnam seems to have crossed the line of making unbiased scientific observation, to taking a biased side in socio-economics.
It’s as if he’s discovered offshore drilling can be hazardous to the environment, and now trying to make endorsements for oil companies because it’s “good for the economy”.
I commend him for making this unbiased observation about group dynamics and social cohesion. But if he’s going to use it to endorse the meddling and social engineering of mass immigration done by the business and political elites, then he better expect some criticism come his way. Many countries don’t have any immigration — like Japan. Yet they wouldn’t be considered a “weak” country. China has no immigration, yet has saw it’s economy grow ever bigger for the past 10 years. Immigration has been western countries lazy solution to dropping fertility rates. There is nothing wrong with a drop in fertility rates, but if your economic model depends on constant growth, then you need immigration to fill in the population gap. This is an economic model we’ve subscribed to voluntarily — it’s not engraved in stone. Immigration is a short-term lazy bandaid solution. It’s a solution politicians came up with because they don’t think beyond their reelection, and business elites just need their cheap disposable labour.