Not so much a subsidy on the item, but on the postal / freight charges. Chinese postal and shipping charges are far lower for any given item, be it your reducer to a 40 foot container, if paid in China, as opposed to if paid in France, the UK or USA for the same journey. I have traded with many countries over the years, and also lived, run businesses in many, never have I lived in a country as expensive for me to send items from as France. But there are probably countries even more expensive to post or ship from. Most of us are not in a position to know how much are the postal or freight charges ( subsidised or not ) of suppliers in other countries.
An example..
In 2024 I was in negotiations with various companies in various countries to source slate "blanks" knowing that I might have to cut down what was supplied. I live in a slate producing area of France, as witnessed by the roofs of many of the buildings in Brittany, including that of our house ( near 100 years old ), roofed in authentic Breton slate. First "discovery" ..only one slate quarry still working in Brittany..only one size available 40x40, only available for "historic restoration work".All trade suppliers in Brittany and elsewhere in France only offer various grades of Spanish slate or Brazilian slate. looked at many, quality was not good, expensive and too variable in thickness.I tried Wales , I used to use a lot of welsh slate when I was in the UK nearly 50 years ago, I bought direct from the quarries. Now the welsh quarries have become expensive , their slate is a luxury item.I even spoke with one who are using a design I gave them back in the 70s, it is selling well for them, that they know it is my design, and it was given at no charge, did not tempt them to offer me any discount.
The freight charges from Wales would have been 5 times the freight rates from Spain.Plus there would have been the "Brexit" effect of delays and paper work.I used to import other items from the UK ,one such item I was the exclusive distributor / stockist for France ..I stopped doing so when Brexit happened, freight charges rose massively, and again complex paperwork.The company is no longer operating.
So , I tried China ( China export a lot of slate of various types and finishes, all good quality) India does similar,India exports a huge amount of "monumental stone"( gravestones and granite work tops exported as slabs or kits ) I've known one of the major UK importers for decades, he also owns quarries in India..but he doesn't do slate..He suggested China.
I eventually found a genuine quarry / producer in China.As in many countries, many present themselves as "the factory" , but they are middlemen operating from a website , an ad in alibaba etc and out of a broom cupboard, but they'll take your order and then ( if you are lucky ) look around for someone to sell to them what you had ordered.
So, my Chinese supplier ( I know they are "the factory" , because they live streamed to me a video of themselves in their factory writing my name on a card on the "shop production floor" and then a 5 min tour ). I liked what I saw and asked for 100 pcs as a small sample order. They immediately came back with " better to order 200, as 100 will cost you $80.00 inc freight , customs and VAT, but 200 will only cost $110.00 as we get much better freight rates per kg after the first 20 kg "
I had already been in contact with french customs for the customs code and duty rate for the items.. The Chinese gave me the same information and said the prices are "all in duty paid freight paid, to your door, no extras"..a second call to customs here in France confirmed what the Chinese said..
My initial sample order is now paid for and on it's way, will arrive around the end of March 2025.
For curiosity I contacted the french company who will deliver and asked them about sending the same weight of item to China..their quote was 20 times more, for the same journey ..I then asked them to quote me from China to me..their price was 15 times the Chinese price, when I pointed this out to them their reply was "sir is not supposed to know what the rates are that we use in other countries, how did you get this information".
I have also since found a supply of genuine Breton slate, the villa next to us is having major work done and is changing their slate roof ( about 30 years old , maybe 40 max ) to zinc..the slates were to be scrapped.I asked the owner and their builder if I could have them, they said "sure" ( I think they feel somewhat guilty about the disruption to us as the work on his place will last well over a year, we are on a private road, they need to park some of their stuff on our land ), the builder has removed all slates carefully. I now have around 6000 genuine Breton slates stacked at the end of our garden.
Postal rates are set by international agreements, so a stamp paid for in one country allows for the letter to arrive at the destination in another with rarely any "surcharges" at point of delivery, it has to work like that , or no letters would move. Likewise internationally, similar agreements apply to packets, or companies take care of it all "door to door", the "sender's rates apply". Customs tariffs are something else..Countries can impose tariffs, but it is the end customer in the receiving country who pays the tariffs, not the sender.
Tariffs on luxury goods ( a threat made by Trump to the EU ) won't make much difference , anyone ( or their 1st lady wife ) buying an imported handbag at over $5000.00 and up to $100.000.00 in the USA that is subjected to tariffs "don't really care" ( to coin a phrase )..but Joe Schmoe who hasn't seen the egg price fall ( battery eggs are currently twice the price in the USA as organic eggs are in the french super markets ) is n't going to be happy when the spare parts for his Chinese laser or plane or bearing or whatever the vital part ( made in China ) in what he has that is written "made in USA" breaks and customs either wont release it, or ask for more money before they'll hand it over.
Unilaterally changing the postal rates that China uses isn't likely to happen as it suits far too many people on the receiving end in far too many countries, including the UK and the USA. A better question might be "why are other countries rates so high". In France the answer is easy, the postal service has a 70 billion euro shortfall in it's pension "set aside"..and it is growing yearly..it increases postal charges at more than the true rate of inflation every year.Fewer people use it than used to. so it puts it's prices up, so fewer people use it, etc.We now have some competition for parcels at least..for now only for inside France..I use them for sending all my parcels to my customers, they are cheaper than the french post..and the parcels arrive intact..they don't get "lost" or arrive "opened".and their staff are helpful and welcoming , unlike the postal service ones behind the counters , who are often ( to translate a local phrase ) about as helpful and welcoming as a prison door.