“Nothing can be done without preconceived ideas; only there must be the wisdom not to accept their deductions beyond what experiments confirm.” – Louis Pasteur

Only demonstrated time-preference can be compared—valuation remains private.revisit

Put differently, A has demonstrated a higher time preference than B, but this does not mean A values the future less than B.

“We cannot compare time preferences interpersonally, any more than we can formulate interpersonal laws for any other type of utilities. The common-sense observation that it is generally the rich who save more may be an interesting historical judgment, but it furnishes us with no scientific economic law whatever, and the purpose of economic science is to furnish us with such laws.” (pp. 415-416)

Related:revisit