How is it defined? Usually understood by whom? Are you talking about abstract concepts or historical examples of "free markets" and their development?
Cartels and monopolies are the result of "free markets" btw. The strongest agents will organize to dominate and destroy the competitors however they can.
The free market is an abstract concept, one which rarely exists in anything like its ideal form due to its instability under current conditions of capitalist development. The original definition given by classical economics is still the prevalent one. Despite what slogans from some proponents of capitalism would have you believe, not only are free markets not identical with it, but capitalism tends to take markets further and further from anything resembling their theoretically ideal state of freedom.
'Free-markets' has never referred to a philosophical, moral or spiritual idea of freedom, except when used rhetorically in discourse by the right, especially since Thatcher and Reagan, i.e. the full onset of the Neoliberal counter-revolution.
Economists do not study the idea of 'freedom'. That is a philosophical concept. When they say 'free', and you actually look at the structure of the propositions they use, they are referring essentially to the private autonomy of firms as 'free' to the degree that there is no non-private, social, public or governmental interest (it's not only the government, as this definition implies that trade-unions make a market 'less free').
I understand what you mean, but I'd really strongly object to the use you've made of the term though as that is precisely the use which was introduced by the right-wing for the purposes of delegitimizing labour organization by conflating labour organization with the anti-competitive nature of cartels in the ideological and rhethorical climate of Neoliberalism that has continuously fetishized supposed competition and playing off our fear of it while nevertheless tending the conditions that promote cartelization of the global economy to the hilt.
The difference is that cartels are firms controlled by capitalists for the purpose of profit and capital accumulation. They fix prices for this purpose. Workers do not, because by their very nature capital accumulation is the logic of the capitalists' material interests, and so in strong contradiction, in the final analysis, with the material interests of labour. Cartel on this definition you've used would then just mean 'price control'. But is then a monopoly or the government a cartel when they respectively fix or regulate prices? The purpose of the introduction of the term was to refer to new formations, concentrations and centralizations of capital in the late 19th century for purposes of overcoming the economic slowdown of this period. It seems harmful, confused and inevitably confusing to widen the meaning of the word so broadly.
I obviously agree that labour should organize, and there are circumstances in which markets might be tolerated in very restricted ways from a socialist perspective, and in such markets labour should therefore of course be organized in such a way as to control production and therefore prices. But the assumption in your question that markets are 'legitimate' in general strikes me as deeply problematic and politically un-Marxist.
What I mean to say is that in a market system the rational behaviour is to seek to maximise what you get for what you give. Anti-competetive practices are simply the logical way to behave in such a system. Trade unions do aim to use market forces to gain for workers an advantage and that is a good thing.
The market isn't fair and it never has been about fairness.
Ideally we wouldn't have a market system but while we do it makes no sense for the workers to not try and get ahead in it. I consider the market by its very nature crooked and therefore think that engaging in market tactics like cartelisation on behalf of workers is the only way to not get completely ripped off. Take coffee growers for example they are pitted against each other by the buyers and thus live in poverty as competition pushes their wares lower and lower. If they were to cartelise they would be able to afford good things and have the basic dignity of always having enough to eat. Competition in the market makes everyone poorer
so while trade unions are an anti-competetive practice that's only because competetive practices are stupid
Yes I'm aware that's what you meant but that has nothing to do with my point and affects it in no way that you are expanding a definition in a way that has normally only been done by the right-wing, for obvious reasons (Elon Musk loves hammering this point).
"What I mean to say is that in a market system the rational behaviour is to seek to maximise what you get for what you give. Anti-competetive practices are simply the logical way to behave in such a system. Trade unions do aim to use market forces to gain for workers an advantage and that is a good thing." Sure. Up to a point, but you are assuming an understanding of rationality that is perfectly consistent with the neoclassical and neoliberal view of the world. The rational interests of the working class are not limited to restricting their behaviour to maximisation of their income in a private labor market.
"The market isn't fair and it never has been about fairness.". Yeh. Sure. Who said otherwise?
"deally we wouldn't have a market system but while we do it makes no sense for the workers to not try and get ahead in it". Up to a point, sure, except exclusive focus on this has historically and inevitably led to economism and reformism.
"Take coffee growers for example they are pitted against each other by the buyers and thus live in poverty as competition pushes their wares lower and lower. If they were to cartelise they would be able to afford good things and have the basic dignity of always having enough to eat. Competition in the market makes everyone poorer". The formation of unions can be useful but is limited in effectiveness, especially in periods of poor-bargaining power for working class groups such as now, with very low levels of organization. The purpose of supporting unionization, from a communist view, must also include the concern to increase our leverage during period of economic boom so as to be better prepared during downturns for pushes for radicalization.
"so while trade unions are an anti-competetive practice that's only because competetive practices are stupid" - this is vague or ambiguous and it doesn't look like the former point doesn't step from the latter. Also stupid for whom? Why? How? For workers? then yes, as per my point.
Yes you are correct I am arguing from what is the best way to behave within a market system and you are also correct that a market system is not the best way to organise society but as it is the current way we organise our society it's worth considering how to live in it
Yes trade unions won't on their own result in communism
operating in the market competitatively is stupid for anyone. It's like paying double whatever the person you're negotiating with was asking