Mobile wallets and consumer spending in Singapore: Agarwal et al. revisited

Agarwal et al. (2019) analyze the impact of the introduction of QR codes for mobile payments in Singapore. They find that this not only resulted in a significant increase in the use of mobile wallets, but that there was also a positive spillover effect on debit and credit card payments – in particular at small and new businesses. This note argues that the increase in card sales cannot have been driven by the QR code technology. I also proffer an alternative explanation, namely that Agarwal et al. simply capture the concurrent increase in popularity of contactless cards.