Has anyone ever heard of an estimate of a graduate school wage premium (i.e. - over undergrad)? I'm calculating wage premiums for engineering graduate school grads relative to undergrads, and then using Goldin and Katz's (2008) basic supply and demand approach I'm trying to work elasticities of substitution out of that. I'm getting somewhat lower grad school premiums than they got undergrad premiums. It all looks fine - that sounds plausible to me - but it would be even better if someone actually produced these grad school premiums before and mine are comparable. I'm not even sure I'll include the elasticities in the paper - I've got plenty of micro-data, but I'm not working off of many years. The relationship is surprisingly strong, but when a kid with a crayon and a penchant for connect-the-dots can do just as well with a print out of my data, I'm a little loathe to call it an "estimated elasticity of substitution".
If I could verify the magnitude of the wage premium with other literature, though, that would be great.