Sunk Cost Effects for Time Versus Money: Replication and Extensions Registered Report of Soman ()

The sunk cost effect is the tendency for an individual's decision making to be impacted by unrecoverable previous investments of resources. Soman (2001) found that sunk cost effect is weaker for time than for money (Studies 1 and 2) and that the facilitation of money-like accounting strengthens the sunk cost effect for time (Study 5). We conducted a Registered Report of a close, high-powered replication and extension of Soman's (2001) Studies 1 and 2 and a conceptual replication of his Study 5 with an online sample of US American Amazon Mechanical Turk (N = 821). We found support for differences between sunk money costs and sunk time costs in Study 1 (original: ϕ_c = .61 [.43, .78]; replication: ϕ_c = .38 [.31, .45]), yet not in Study 2, in which we found sunk cost effects for both money and time (original: money - ϕ_c = .32 [.12, .52], time - ϕ_c = .02 [.00, .18]; replication: money - ϕ_c = .23 [.14, .33], time - ϕ_c = .32 [.23, .42]). In Study 5, we found no support for facilitation of money-like accounting as strengthening the sunk time cost effect. Materials, data, and code are available on: https://osf.io/pm264/.