I have tested this before actually and find that linking out from the homepage has no effect on anything. If anything, it would effect pr
. But what does pr
actually do is the question? Nothing of course in the SERPS. I have now links from my site to some of my newer business concoctions and so far I have not seen any pr
or serp change. But I doubt very many people in this world can answer this question with any certainty. And many of the sites that kick butt in our industry have links out everywhere. Remember we are measured not just on incoming but outgoing links as well. Google wants us to be part of internet and that also means linking out to relevant sites. Even Ehealth links out 6x from their home page.
In the end because there are like 200 variables to measure, it becomes near impossible to do anything with certainty. So that is why I give my new sites juice, even if there is a small chance that it might hurt the main site.
Anyways it is a great question but anyone that answers it with certainty unless they work for google can safely be ignored. In the meantime just get high pr
backlinks and all other issues can resolve themselves. I do remember that Matt Cutts himself said that Wordpress out of the box solves 90% of SEO
issues without touching anything.