> The first thing that can reduce conversions is the higher rate of 3DS triggered user abandonment. Since many consumers are not familiar with the 3DS process, there is a higher chance of abandonment during the authentication process.

This would presumably go away once PSD2 is fully implemented and all purchases require it, which is a benefit of requiring it by law rather than letting merchants choose whether or not to require it. Requiring it is a common good in the sense that it reduces the economy's overall loss due to fraud.

Additionally, as the article mentions, using 3DS shifts liability for charge not authorized disputes from the merchant to the bank. Thus, the decreased rate of conversions must be compared against decreased losses due to chargebacks.