A few quick thoughts:
1. The opening post asks: "How effective are economic or business sanctions?"
Doesn't specify "effective" in
what. What is the goal? Is the goal measurable such that we could compute a specific effectiveness in terms of, say, x billion US$ per 1 unit of Z, whatever the target variable Z?
2. Someone mentioned Russian consumers stockpiling sugar on a rumor that there is a shortage in sugar, and this results in an actual shortage in sugar in stores.
The exact same happens currently in Germany, with (sunflower seed) oil and (wheat) flour: People heard that we import much wheat and sunflower seeds from Ukraine and Russia, so people rush to stockpile those products, with the results that shelves for oil and flour are indeed empty. I am currently out of wheat flour and can't buy any[*]. This is in Germany! The problem is not any sanctions, the problem is irrational behavior in reaction to news.
[*]ETA: I still do have flour of buckwheat, chickpeas, spelt and rye, and I think those are still available in stores, as people are slow at adopting these great alternatives. My experiments in pancakes can and will continue unhindered
).
3. Someone claimed that the US could seize the US$ that European customers give Russia in exchange for the Rubles they need to buy natural gas. This is not a given. I am sure Russia's plan is to have those currencies transferred to a place where it can't be seized.
4. Someone reported that Lithuania just decided to buy no more Russian gas.
This is a bit self-serving and probably makes no difference in fact: Gas streams from Russia through a small number of pipelines into a small number of hubs inside the EU, from whence it gets distributed to all connected member states. There is a grand total of 100% of pipeline gas that gets shoved around at any time, of which X% comes from Russia, and 100-X% comes from countries other than Russia. If a small country like Lithuania decreases its purchase of Russian gas to zero, that volume will slosh somewhere else, and some other countries will import a tad more Russian gas. Or not even that: At any time, the actual gas that is burned at some specific location may have originated from Russia, or from some Liquid Gas terminal, or even from a storage facility that has mixed Russian/non-Russian gas.
This is similar to me having an electricity contract where I purchase 100% renewable power: Of course when I heat my home with electricity on a windless night just to hurt Putin and his war by not using his blood gas, the actual electricity produced at that time will be close to 100% non-renewable. What happens there is merely a trick of accountancy: I purchase the renewable energy that someone else uses during the day, and in return use the non-renewable energy that someone else pays for during the day. As a result of me reducing my non-renewable use (on paper), someone else (probably some industry) increases their non-renewable on-paper share of energy.
5. It has been said a lot - but not really in this thread: Sanction almost never work to achieve their grand objectives, like deposing dictators, ending wars, freeing peoples or causing democratic revolutions. They just don't. It is well known that they even tend to stabilize authoritarian regimes.
What they MAY achieve is slow down economic and particularly technological development, and thus decrease somewhat (by "y%") the real capacity of the targeted regime to project harm - like build up / maintain their military, slush funds for bribes and terrorists, etc. In fact I have seen it claimed that the sanctions against Russia since 2014, particularly in terms of technology transfer, have had effect towards the bad state of the Russian armed forces that we are all surprised to witness in 2022.
6. I think it is pretty straightforward that purchasing less fossil fuels from Russia directly hurts the country and particularly its elite.
But as Europe has neglected to seriously phase out the use of fossil fuels with absolutely the highest priority of all, it also hurts Europe's economy directly - only this time everybody, in the form of higher energy prices (which directly trigger inflation, as every wealth produced contains energy) and (if there will be actual shortages with Russia switching off the supply) loss of industrial production.
This will, in the long run, be a bigger problem for Russia - and by long run I mean at least >5 years, perhaps >10 years. After that, it will be a win for everybody.
I thus tend to be in favor of risking our gas supply. Scarcity has a way of making people clever and industrious to find solutions, quickly.
In the long run, we just need to keep most of the remainder of the fossil fuels in the ground, forever. We need not deplete Russian gas nor that of Qatar, nor the oil of Venezuela. I have a faint hope that, decades down the road, history will describe this war as the turning point towards getting a grip on global warming.
