Metrics and evaluation of scientific productivity: would it be useful to normalize the data taking in consideration the investments?

There has been in increasing interest in evaluating research production by means of "objective parameters" which should score the scientific impact of single articles and researchers' career. In contrast, the attention of the economic aspects of research production has been highly neglected. I suggest that introducing the assessment of the return of research investment would be useful for fair comparison among researchers and probably it would render more understandable to public opinion what are the criteria according to which research funds are distributed.