Marxists and Conservatives have more in common than either side would like to admit. This thought occurred to me whilst reading a superb piece by Andrew Lilico.
He describes the Brams-Taylor procedure for cutting a cake in a fair way - in the sense of ensuring envy-freeness - and says that this shows that a central agency such as the state is unnecessary to achieve fairness:
Provided that all adhere to an appropriate mechanism, large numbers of people themselves, without central direction, can divide goods, services and assets up in ways that all consider fair.
The appropriate mechanism here is one in which there is a balance of power, such that no individual can say: "take it or leave it."
This is where Marxism enters. Marxists claim that, under capitalism, the appropriate mechanism is absent. Marx stressed that capitalism was founded upon theft and slavery - what he called primitive accumulation, a process that is still going on. This means that the labour market is an arena in which power is unbalanced: the worker, he said, brings only his own hide to market "and has nothing to expect but — a hiding." Exploitation occurs and matters, says (pdf) John Roemer because it is the effect of "an unjust inequality in the distribution of productive assets and resources."
Nor do Marxists expect the state to correct this, because the state is captured by capitalists - it is "a committee for managing the common affairs of the whole bourgeoisie." Marxists smile at the naive centrist utopianism of social democrats who complain about "corporate welfare", because they fail to see that, under capitalism, it could perhaps only rarely be otherwise.
Instead, Marx thought that fairness can only be achieved by abolishing both capitalism and the state - something which is only feasible at a high level of economic development - and replacing it with some forms of decentralized decision-making. There has always been an affinity between Marxism and anarchism, with many Marxists regarding Stalinism as the negation of Marxism.
In this sense, Marxists agree with Andrew: people can find fair allocations themselves without a central agency.
But can they do so under capitalism? One hope that they can lies with trades unions. As Philippe Aghion has pointed out, strong unions are a substitute for minimum wage laws because they ensure a balance of power which facilitates fair labour bargains without state intervention; it's for this reason that Conservatives should in fact support unions.
Herein, I suspect, lie the big differences between Marxists like me and Conservatives like Andrew*. One is: what constitutes a reasonable balance of power? Another is: would a "fair" labour bargain actually be consistent with healthy capitalism, or would it instead lead to a squeeze on profit margins so severe as to deter capital spending and hence depress growth?
* I fear both of these are small groups.