They will pay more because currently the cost is partially covered by the USPS. Such treaty makes sense in two cases:
- the cost of recovery is high. 140 years ago, doing the accounting for all the parcels, letters sent from France to the US would have cost and from the US to France to then "balance" the accounts would have been way higher than the recovered money from one party.
- the traffic is balanced, that is, both countries send/receive approximately the same numbers of parcels/letters each way, each year.
Once these two assumptions do not hold any more, it makes sense to reconsider the situation. This is a question of balance.
- the cost of recovery is high. 140 years ago, doing the accounting for all the parcels, letters sent from France to the US would have cost and from the US to France to then "balance" the accounts would have been way higher than the recovered money from one party.
- the traffic is balanced, that is, both countries send/receive approximately the same numbers of parcels/letters each way, each year.
Once these two assumptions do not hold any more, it makes sense to reconsider the situation. This is a question of balance.