Economist Jobs, Blogs, Resources, Videos
Only quickly looked at this site (obviously since you have just launched it) but one improvement would be to keep the content more closely linked to things relevant to economics. There are a lot of things linked on here (for instance in the applications section) which involve things like dating, computer games, webmail etc. Pretty much as soon as my employer spots that these things exist it will block them (and probably the whole site) as they violate electronic media policies.
Similar IT policies probably apply to economists in other government departments as well (and probably a lot of those in the private sector) so keeping the content more focused is likely to help.
All looks good....except I've spotted a typo in the site design - "Environment"
I don't know about others, but I think this is the kind of social network where real names, rather than internet handles are more appropriate. Could we have an explicit message to say users must use their real names? Surely the whole point of this social network is that you are able to identify people from here in real life and vice versa. Pseudonyms make that quite hard.