COST SUBJECTIVITY . . . run it by a CEO and run it by Rachel Maddow, see who's onboard.
In case you missed the edits:
I see it. People can easily assign different "weights" to various cost components at various times, leading to differing final values about the overall cost of a particular action. Cost and benefits being subjective is a fairly critical feature of AE.
I am more specifically referring to C/B analysis applied to political action and society, which is infinitely more complex than traditional business CB analyses, which focus on much more narrowly defined questions with fewer variables, and (usually) a very clear criterion for success (bottom line).
That is to say nothing of the moral or ethical issues in play, which are the most important aspects anyway.
EDIT: To give an (extreme) hypothetical to illustrate the principle, please explain A) which of these costs are ideal on the sum, and B) explain how a person cannot arrive at any other conclusion, thus proving it's objectivity. Assume everything else is equal.
A. A policy that decreases wealth by 6 percent on average, kills 1,000 people, and jails 1,000 people
B. A policy that decreases wealth by 37 percent on average, kills 0 people, and jails 0 people
C. A policy that decreases wealth by 0 percent on average, kills 1,000 people, and jails 4,000 people
Here is a paper that touches on some of these issues:
http://mises.org/journals/jls/4_1/4_1_6.pdf