USPS just delivers letter mail at much lower rates than the others. And does so at a fixed rate to any address within the US, whether that's a neighbor across the street or a family member in a tiny town in the mountains.
https://about.usps.com/universal-postal-service/ilo-report.p... (PDF)
Personally, most of the mail I receive from USPS is garbage. And my mailbox is located at the end of the block, clustered for the whole neighborhood. Due to both those facts, I rarely check the mail - it's often overflowing by the time I bother.
The mail I receive at my door (non-USPS) is 99% not junk. I don't have to go out of my way to retrieve it. And it's more likely to be dry (because the screen door never gets overfull of mail like the postbox).
Just an anecdote, not meant as anything more.
Their competitors certainly claim it gives the USPS a significant advantage, if you check the info I provided. They also give reasons for their view. Are there any particular reasons you think they're wrong?
https://www.law.cornell.edu/uscode/text/18/1708
I'd wager that "porch pirates" don't go into mailboxes even though there's valuable stuff in them.
> The USPS actually has two legally enforced monopolies, as per Title 39 of the US Code. One is over the delivery of anything defined as a “letter,” which is within certain size and weight limits. The second is over the use of your mailbox...there are criminal violations if anyone puts anything in your mail box that is not US government approved “mail.
> ...parcels were never subject to the delivery monopoly. Indeed, UPS was in that business first, and USPS entered afterwards. ...This is why DHL, FedEx, Amazon... and others are free to enter and exit the parcel business. It is defined as a different market.
> FedEx is another fascinating story. There was a need for express document delivery among professional services, such as law firms (this was of course long before e-mail). The USPS was too slow and unreliable. FedEx and Fred Smith threatened to litigate the issue to death...so the USPS allowed an exception in the delivery monopoly for “extremely urgent material.”
https://fee.org/articles/an-expert-explains-the-postal-monop...
Enforced where I am.
ADDED: IOW, you could have an external taxpayer-supported "rural mail delivery" department that has a charter to deliver a letter for a quarter anywhere in the country rather than providing a subsidy within the system.
It's mostly academic at this point. (And the reality is most private package delivery is fairly universal because there are business advantages to having a fairly complete delivery network even if it's not necessarily the most efficient decision at the micro level.)
I don't think empirical data are especially kind to it.
It also ignores the fact that monopolies have no incentive to produce high quality and ever improving product. They tend to get focused on maximize staff comfort over customer satisfaction.
I would hate to have multiple companies completing to efficiently deliver ever larger piles of junk mail.
For one of the odd cases which details the weird world of USPS laws passed by Congress, check out Postal Service v. Flamingo Industries which starts with claims of attempts to create a mail sack production monopoly and goes interaction complicated from there. I was not aware the USPS has the powers of eminent domain and to conclude international postal agreements.