Tariffs can also be an effective way of balancing buisness advantages. An example: Germany has quite high standards in its farming sector. This applys to what pesticides you are allowed to use, how much fertiliser you can use, what conditions animals have to live in and so on. Everything that you have to do to comply with these rules costs money, so in order to still make a profit you need to charge quite high prices. If you then compare these with the almost non existent standards of, as example Brazil, you quickly realise, that they are capable of producing goods much cheaper (who could have guessed, that its cheaper if you can just imassively increase your land by land grabbing, giving a shit on everything and using the most efficient, but very cruel, ways to feed and hold your livestock). Due to this, beef that gets imported into Germany from Brazil, thanks to Mercosur without any tariffs, will be magnitudes cheaper than locally made. This kills your local farming sector and also does massive damage to Brazil’s citizen and enviroment (its a massive brainfuck how farming works there). If you want to counteract this you could charge tariffs, so that the consumer starts preferring locally made products, because they are cheaper. This also is an incentive for Brazil to better regulate its farming industry.