I don't see how you conclude that I'm pro slavery, is not just bad conclusion but distortion of what I say. The difference between slave labour and wage labour is in that the slave doesn't own his labour, the worker does. I thought you have read Marx and you understand, but it seems you haven't, so, by labour I mean labouring power or the possibility to work. In slavery or feudal relations, it was not the labourig power that was commodified, but the human, commodification of labouring power appears with capitalism. Profits are not created by the individual intervention of the capitalist but by the collective labouring process. In job market, as you call it, but actually is market of the possibility to work, you actually trade your possibility to create value and profits which the capitalist uses as resource to get profits (you have even human resource sector in all companies). In this process the labouring power becomes good that the capitalist consumes, which is bought on market, the market sets prices same as for any commodity. The labouring power in this relations gets all characteristics of a commodity, it is good to be consumed on market, there is someone who sells it, and is not payed by the value it produces (use value) but by the prices set on the market (exchange value) of jobs. Actually this process of commodification is something all liberals and right wingers ignore, and there is a reason why, liberalism as ideology comes to life from the interest of the young bourgeoisie in feudal society which yet had to be established as ruling class, it has in itself the social position of the capitalist, his approach to himself and that is why is fully individualistic. The fact that is ignored usually about USSR, SFRY and Mao's China in connection to labour is that they had no job market, job was no something you could deal with the manager, but right, the prices of job were not set by market, but by the productivity of the labour and the conditions together with the value it created. This is what made those economies not a capitalist economies (those were not communist for sure, but some form of transitional economies) and the commodification of labour what makes today China a capitalist.
When we are at facts checking... Marx's method of analyzes of history is not dialectical materialism, but historical materialism. Dialectical materialism is something different. So get your information on Marxism from another source not just from Popper. I like Popper's formal logic, nothing new in the 20 century, Lenin deals with this in "Materialism and Empirio-criticism" at time when "the great 20th-century philosopher Karl Popper" was just 6 years old... and of course Popper will reject Marxism... to expect Popper to accept Marxism is the same to expect that the salve owner would accept that colored people are humans, it goes against its interest to exploit them, as we can see from history slave owners could not accept the reality that colored people are humans even when slavery was formally ended. As Donna Haraway explains in her "Situated Knowledges" our vision of reality is always blured by the position in which we are, Popper was rich boy with interest to keep private property to ensure his position in society. We can continue this subject also with Foucault, Walter Benjamin, Louis Althusser... maybe Zhizhek if you want, but it will still be the position of Popper as rich boy in Vienna at time when workers in Red Vienna were in power. I bet it was scary to see all those workers coming for what you have robbed them...
You claim that Engels, wrote that in communism "the state itself would become unnecessary and ‘wither away’. These assertions were not made as speculation, but rather as scientific claims about what the future held in store" to later say "China of pure communism that produced the famine and terror of the ‘Great Leap Forward’ and the ‘Cultural Revolution’". So there is contradiction even in formal logic here, or Engels was wrong, or China never have been in "pure communism"... and I don't remember that Mao ever stated that China is communist... this "dilema" becomes obvious when you see that not a single Marxist claimed that any country was communist, if this is untrue I'll be glad to be provided with the Marxist who claimed that. It is a question of switching theses, same as Popper does to protect his rich ass from the workers gaining power in Vienna...
See, this is what you don't understand about dialectical materialism, not historical, dialectical... things develop in contradictions as unity of opposites, not in a linear manner. What at certain point opens possibilities, at other point becomes obstacle. China's total debt is quite big, and what enabled China to restart production faster than EU or US is the control the state had on production, so I'm not so sure which is plus which minus in the story... but anyway China's economy is not so stable without growth and expansion of the market (which is characteristic of capitalist economy), so lets not rush in conclusions for which even the CP of China doesn't have such optimistic views...
Ok, this "inefficient state-owned enterprises" has already become false argument... Look at the British Railways and studies on them... what is the measure for efficiency? Profits? Of course you will have more profits when you make the service more expensive and at the same time cut spending making the service with lass quality... but the question remains, what is efficiency? What use do people have from the profits if the service is with lower quality for more money? Abstractions of pure economist position...
Yet another mistake... "Marx regarded private property as the source of all evil in the emerging capitalist societies of his day." Marx doesn't deals with moral questions of good and evil. Second, Marx, later Engels, claim that private property is result of the division of labour and the bases for the creation of the state in certain historical times, not in capitalism, and as such is not eternal, it will stop to exist when the material conditions for its existence will no longer exist. There is no religious morality there, just observation and analyzes of haw and why private property had appeared and which relations with it were brought to existence, such as oppression and the family together with the conditions which force people in to action to protect their lives. And this is not dialectical, but historical materialism...