Country A sets up a standard or regulation that will make some product more expensive (labour, safety, health, or environmental, but sometimes protectionist). Country B does not have this regulation so its product will be cheaper. What to do? https://twitter.com/EvanHD/status/1335862603135016961

Solution: a tariff. Country A puts an extra charge on an import, bringing competing product to the same or a higher price than the local one, you might call it 'levelling the playing field'. This price is charge is paid by a person in Country A buying Country B's product.

Tariffs are an administrative pain and quickly become political (local industries lobby for tariffs to protect themselves etc), and make trade slower and more difficult, this is called 'friction'. They are bad for economies! Hi, 1930s.

Country A and Country B might want to remove friction from trade broadly. To do this they negotiate a 'free trade agreement', where they globally remove tariffs by agreeing to shared standards.

Nobody applies a tariff on a product made to a higher standard. This is not a thing, because then that product will be more expensive and so not need a tariff. And yet mysteriously this is the example the UK government keeps using to explain why tariffs are unfair.

Actually it's not mysterious because what the UK government doesn't want to say out loud is that the point of Brexit is to lower our standards of health, labour, and environmental protections to compete with the EU.

The other reason the UK gov doesn't want a level playing field, is that tariffs are also used to combat subsidies by foreign govts. Let's say Country A is giving government money or tax breaks to a local industry, making it more competitive than Country B's.

Country B would then have to put a tariff on Country A's product, to 'level the playing field', or subside the industry themselves, or have their local industry go under. Subsidies are a big source of friction even with a free trade agreement because they can be hard to quantify

Enter Dominic Cummings, whose grand plan is to run a sort of command economy pouring billions into government-funded tech (run by him I guess). This is not a level playing field, if your tech company can get a massive subsidy by moving to London from Frankfurt or whatever.

You can see how it would hard to figure out what a subsidy is, how much it disadvantages local industry, not to mention what the shared standards should be. This is why Free Trade Agreements need dispute mechanisms that both countries feel are fair and representative.

Especially if one country had recently proved itself to be a disingenuous rat-bastard who breaks international agreements.

Anyways I'm not an economist but I am a Canadian so tariff wars with our massive neighbour to the south have the power to blow our economy back and forth with every breeze, and so regularly dominate the headlines, and our journalists do a much better job of explaining them.

So welcome to tariffs UK, you had better start to wrap your heads around them because this is your life now.