An asymptotic hypothesis test for value-at-risk subadditivity is introduced and studied. The test is derived based on … an equivalent formulation of the value-at-risk subadditivity inequality in terms of the distribution of the underlying …

subadditivity. Design/methodology/approach We conduct an online randomized experiment with 3,980 employees. Findings We detect a … certainty effect (upper subadditivity), whereby professionals are willing to devote a disproportionate number of hours to a … likelihood of success by the same percentage points. We find no evidence of the possibility effect (lower subadditivity), whereby …