Die Dis cus si on Pape rs die nen einer mög lichst schnel len Ver brei tung von neue ren For schungs arbei ten des ZEW. Die Bei trä ge lie gen in allei ni ger Ver ant wor tung der Auto ren und stel len nicht not wen di ger wei se die Mei nung des ZEW dar.Dis cus si on Papers are inten ded to make results of ZEW research prompt ly avai la ble to other eco no mists in order to encou ra ge dis cus si on and sug gesti ons for revi si ons. The aut hors are sole ly respon si ble for the con tents which do not neces sa ri ly repre sent the opi ni on of the ZEW. AbstractUsing the introduction of the euro as a natural experiment, we provide economywide evidence for money illusion based on declared donations from German administrative income tax data. Our results suggest a magnitude of the money illusion effect between 2.4% and 7.6%. Compared to previous studies on money illusion in the course of the euro currency changeover this effect size is significantly lower. We trace this back to the more comprehensive donation data in our study compared to hitherto studied face-to-face collections, which makes our results less prone to "power of the ask" and social pressure effects.