Value of Authoritative outbound links

I thought this was interesting.

I did a site for a Civil Engineering Company who wanted to have an online presence, but really weren't "selling" anything other than employment opportunities. The Company pres. asked me to create a comprehensive list of Civil/Survey related sites for visitors to browse. I created a links page with only outbound links, mostly to government agencies, some associations and some authority and university sites. I was not much into seo at the time and really put no effort into optimization at all. I submitted the site through some free autosubmit sites and forgot about it. The site's been up for about 18 months and when I went back to check on it recently it had a pr 4. This is with no effort to pull inbound links at all.

So, is the pr from just the outbound links? Can I boost my pr that much with an authoritative outbound links page? My pr is at 3, would that maybe take me to a 4 or 5? Obviously there is quite an effect at least on the above site!

PR can only be generated by two methods... 1) getting inbound links from other sites and 2) building pages (each page has a tiny tiny amount of native PR that it can share with another page by linking to it).

The PR in this engineering site is probably a result of inbound links. Lots of universities like to link to professional sites and it is possible that your engineers have purchased advertising on another website.

The president is not savy enough to know where to advertise, but they may have gotten some inbound links without even knowing it I guess.

According to google they only show two minor inbound links and seven internal links, yet all their pages are pr4.