A company wins a contract of value (100). A number of company workers implement the contract. How much, out of the (100), should they be rewarded for their work?
Liberal: Market laws dictate the renumeration of the workers. The company will consider the renumeration in terms of opportunity cost. If it can find a cheaper solution it will just go for it. In this way a stable and acceptable wage is reached
Social-democrat: State must provide for a safety net and tight working regulations. Minimum wages must be secured and must be able to create decent worker living standards and social cohesion. Of course, this results to taxes. A good portion out of the (100) should go to this security net. Beyond that net, market laws must be let to operate, just as in the above case.
Communist: There is nothing like a market law. It is capitalist trick, local in time, that will be abolished in time by proletariat action. All value must thus be delivered to the workers. The company should cease to exist, should be owned by the workers or by some neutral and not profit representative of them (state, cooperative, etc.)
The above question has been on the table for such a long time and still finds a lot of controversial answers and a lot of supporters behind them. This demonstrates the wisdom of Carl Marx, who considered the conflict between labor and capital a fundamental issue of our society. The fact that numerous idiots and criminals wreaked havoc on Marx's name is just a reminder of what typically happens when the great minds go away and their followers try, with their, typically little minds (and hearts), to practice them. See the case of Christ and the “Holy” Inquisition, the case of the French Revolution and the terrorism that followed, etc.
As long as this conflict is there and remains theoretically unresolved we cannot claim the liberal is wrong. We can however claim that he is unethical. A liberal, in his opportunity cost approach, would find absolutely correct to have a 6 year old kid in India load a truck with stones for 10 USD. A lot of people would not, whatever the opportunity cost. (Of course many of us hold their own responsibility at this point; we choose COMFORT and pretend we know nothing or say we can influence nothing about the goods we buy and how they come along to us so cheap... [welcome comment from my friend Marysia Goreczna- Poland])
We cannot even claim the communist is wrong. We can however claim that his ideas where put in practice for many years and only resulted to unprecedented misery, corruption, crimes and devastation, moral and physical. It is unthinkable to allow ourselves such a large scale experiment once again.
The social- democrat takes a way between. His world builds on both markets and ethics and avoids extremes. Even for this only, his model is more stable, more wise, more acceptable.
Ancient Greece taught and practised (unfortunately with notable and catastrophic exceptions, such as the devastating Peloponnese war when shortminded extremists [*] prevailed), for the first time in history, the wisdom of the the "path between" ("Metron Ariston", "Miden Agan") . This is maybe one of the many reasons that Ancient Greece was so much appreciated by Marx himself...
(*) Perikles holds, unfortunately, the main responsibility for the intransigent attitude of the Athenians against Sparta. A tragic irony: that great man, of the Golden Age, the greatest age, ever, failed to realise the dead end of his extremist policy against the Spartans, opening the way to the demise of Athens, the heart of the Hellenic world.