Mihi, at IMHO, writes about measuring productivity of programming languages:
The main problem is to compare these languages. A common method is counting the “lines of code” a programmer needs for a given program. But who is going to implement the same specification in hundrets [sic] of languages? So to make the test applicable we need a common concept for the comparison.
The common concept that he talks about is function points.
In answer to his rhetorical question, there have been a few studies that have asked several volunteers to solve a standard programming problem in the language of their choice. Peter Norvig’s refers these in Lisp as an Alternative to Java. First there was Lutz Prechelt’s Comparing Java vs. C/C++ Efficiency Issues to Interpersonal Issues, which he followed with a study that included Perl, Python, Rexx, and Tcl. Finally, Erann Gat collected some numbers for Lisp.