I've previously critiqued the mighty mug example. It has the exact issue I pointed to above - comparing the US retail rate to an international sorted rate. See https://news.ycombinator.com/item?id=21073682
Your claim was disproved back then and it's still false now. You were comparing the shipping rates for someone who does all the sorting and long haul delivery vs China, who just dumps all the mail at the Port of Los Angeles, sorted into buckets by zip code.
My understanding is Amazon roughly passes through their costs on FBA. Regardless, I pointed at the cost that anyone who ships reasonable volume and does similar sorting to China Post can access.
I was not doing a comparison, I was showing how the NPR numbers were dishonest. NPR claims that it costs $6.30 to mail something across the street. They never give a specific number for a shipment from China to compare to.
Prices have gone up since then, but even today the most expensive option with no pre-sorting for 13 oz is only $5.39. It can go as low as $2.36 depending on the level of sorting.
NPR is clearly not doing an apples to apples comparison, and nobody has tried to defend them, they just attacked the numbers I sourced.
Now, you're saying that China does full pre-sorting to the zip code level but doesn't deliver to the closest location. This is roughly equivalent to the 5-digit DNDC option, which currently costs $3.56 - maybe slightly more because I don't know the exact details of how China delivers to the US. And it was lower at the time of the NPR article, which claimed the domestic price would be $6.30.
> This is roughly equivalent to the 5-digit DNDC option, which currently costs $3.56 - maybe slightly more because I don't know the exact details of how China delivers to the US.
China the country does that, but that cost is not borne by the shipper in China. The shipper in China just drops the item off at their post office.
But regardless, China then pays the US $1.90 to deliver that package for them. You will not find any service available to a US mailer that is only $1.90.
This [0] has numbers from 2015, which are older, and it doesn't have a full breakdown, but it says that 200 grams (or around 7 oz) would cost $2.67 as the cheapest option through China Post. The next option is 500 grams which is 17 oz, at $6.67. 13 oz would probably be somewhere in the middle. And of course US prices have gone up since 2015.
From the rates that I've seen, I don't see how they can possibly represent the real cost of shipping some of these items. They aren't injected into the USPS system close enough to the destination to be comparable to something like SmartPost for example.