There is as far as I know, no reliable statistical data to allow a definitive answer to this question. By this, I mean there are no well conducted, randomised blinded controlled trials comparing different procedures with respect to residual refractive error. As I mentioned in another answer, a Cochrane Database meta-analysis showed similarly good outcomes between LASIK and PRK at one year, but this is in no way a 'statistical' validation of their equality.
There are many factors that can contribute to 'residual degree', and the type of procedure used is probably a minor one when compared to the others. Also, bear in mind that in the first place, significant residual degree after laser refractive surgery is a rare occurrence.
