Economic experiments often entail subjects making decisions with payoffs in experimental currency units (ECUs). Earnings in ECUs are converted to cash at the end of the experiment. Such a procedural choice seems to be driven more by habit or tradition than by empirical evidence that this is more appropriate to use. We report results of a private, induced value second price auction (SPA) experiment in which we manipulate the exchange rate between ECUs and cash. We find virtually no relationship between a stronger/weaker experimental currency and the ability of theory to predict observed outcomes. The only significant effect relates to the comparison of the cash-only condition to the one-to-one exchange condition. The latter produced greater behavioral deviations from theoretical predictions. However, we find that this effect is largely driven by a handful of subjects. The results suggest that the use of ECUs is not a hindrance for experimental practice, at least not in the context of an induced value SPA.
