Google has made its stand clear on PageRank dissipation between 301 redirects and normal links. Matt Cutts in a video said that PageRank dissipation is roughly the same between 301 redirects and normal links and as such no percentage of PageRank gets lots by using 301 redirects.The video given below is rather confusing but the essence is – you may use any of the linking techniques without focusing on how much PageRank would be lost?
Here is what Matt says:- The amount of PageRank that dissipates through a 301 is currently identical to the amount of PageRank that dissipates through the link. It means use whatever is best for your purposes because you cannot serve any more PageRank if you use a normal link and likewise it does not hurt if you use a 301.