As a way to summarize some of the activity on the Networks class blog, the course staff will be posting to a “digest blog” that will run in parallel with the main class blog. Once the blog schedule gets up to full speed next week, there will be more content than we can possibly hope to summarize, but the idea in this digest blog will be to point out a few of the posts and link to further reading on some of them.

To get this underway, here are a few of the ideas that have been discussed on the class blog in the past couple of weeks. A number of posts have concerned the ways in which information, ideas, and behaviors can spread through social networks; this will be a large topic in the second half of the class. In particular, pmd8 talks about a widely-read study from this past summer on how obesity is “socially contagious” — although you don’t “catch” obesity from your friends in an epidemiological sense, the probability that you become obese is significantly higher if your neighbors in the social network are obese. jld263, in the first post of the semester, talks about the Genocide Intervention Network, which aims to spread information and awareness about situations leading to possible genocide, and to facilitate fund-raising in support of the prevention of genocide. And ninjaspleen talks about recent work of Duncan Watts that calls into question whether people who are typically deemed “highly influential” in a social network actually have the impact that is usually attributed to them.

A number of posts give nice applications of some of the themes that we’ve discussed in the past few weeks. notamoose considers how structural balance can be used to interpret some of the rivalries and alliances in the Democratic and Republican Presidential primaries that have emerged over the past month. irishlass discusses current developments in kidney exchange, which is an emerging application of matching markets for a medically important goal. dagreg discusses how triadic closure and structural balance naturally operate in the world of massively multi-player on-line games; as we’ve discussed at various points in class and in the book, on-line domains such as these provide us with fascinating sources of data to study such effects at a quantitative level.