Thanks for the link, very interesting. Makes me wonder if 3 years is going to be enough, but also determined to see it through. I refuse to have an unfinished project taunting me for the rest of my life.
I think maybe failure rates also correspond to how much the individual really wants it. Is the Phd a dream to be fulfilled or a stop gap because nothing better came along and reality looked a bit scary.
Many other factors may be involved, and each set of circumstances is unique, but there's alot to be said for dogged determination and refusal to accept anything but success.