I wonder if fraudulent transaction levels are similar in the US to those in the UK and if no, what the reason is for the difference (and if yes, why the transaction costs are so much higher in the US).
One reason why it might be much higher in the US is the prevalence of swipe and sign. In Australia signatures are no longer allowed and essentially all transactions are chip and pin (or tap if its under $100). This basically eliminates in store fraud as a chip cant be skimmed. No idea why ACH is so expensive / terrible in the US compared to other countries, I guess its the number of banks?