[octodog]

The basic premise in market economies is that if a transaction occurs it is beneficial for both the buyer and the seller. This makes intuitive sense if you think about it - nobody forces you to buy McDonald's, you do so because you think a Quarter Pounder is worth the price you pay.

Sanctions work by preventing this transaction from happening, which means both the buyer and the seller are worse off compared to when they are allowed to trade.

The key point here is that although both the buyer and the seller are worse off, one party may be disproportionately impacted. This is the case with the Russian sanctions, as Western companies can usually find other markets (although less lucrative) but Russia is now having serious trouble sourcing certain components.

McDonald's is likely doing this for image reasons or to appease stakeholders rather than doing it to punish Russia directly, but the outcome is that Russians are slightly worse off than before.

[isleyaardvark]

It's also cumulative. It's only one market for each individual seller, but the buyer is deprived of many sellers.