I don't intend to attempt to offer full answers to any of these questions. I have a more modest goal: to think through a particular strategy for answering them familiar to some on the socialist Left. I have in mind the sort of argument (see here) put forward by Lindsey German (formerly of the Socialist Workers Party (UK)). For a similar argument, see this article at SW.org.
Here's German's statement of the argument I'm going to examine:
I want to reject the concept of patriarchy as at best a muddled term simply meaning women’s oppression (in which case it cannot explain this oppression), and at worst a completely idealist notion which has no basis in material reality. I want to show that it is not men who “benefit” from the oppression of women but capital. I want to look at the way in which the family has changed, and how as it has changed women’s conception of themselves has also changed. Hopefully that will demonstrate that women’s continued oppression is not the result of male conspiracy (or an alliance between male workers and the capitalist class), but of the continuation of class society in every part of the world. It follows that I shall argue the “socialist” countries have no more in common with socialism than they have with women’s liberation.So the answer that we should expect German to give to our question "who benefits?" is: the ruling class. But is that accurate?
It depends first on what we mean by "benefit". Suppose that we take "benefit" to simply mean money. What German wants to say is that working class men do not procure monetary benefits from living in a society that oppresses women, but the ruling class does. She offers two arguments in defense of that claim. First, a labor market in which men and women are divided, with women forced to accept lower wages and worse jobs, does not benefit working men as members of the working class. That is, this sort of labor market drives down wages across the board, making all workers worse off. Second, the ruling class directly benefits from dividing and conquering the labor market along gender lines, since the strength of a united class would be far more effective in bargaining for a larger share of ruling class profits. Notice that this is a counter-factual claim. That is, it asks us to imagine a contrary-to-fact scenario (i.e. one in which the working class isn't divided, but united) in order to make its point. Since a united working class, one without internal hierarchies and relations of domination, would be much better for all workers, it follows that internal inequalities within the working class are not in it's long-run interest as a class.
Now, for my part, I think both of these arguments are sound. First of all, a divided labor market is worse for workers and better for employers, hence why employers love "two tiered" pension plans, etc. etc. When workers compete amongst themselves for jobs, be it through "legitimate" means (i.e. by "meritocratic" means) or "illegitimate" means (i.e. by means of coercion, power, etc.), capitalists benefit because this increases their bargaining power vis-a-vis labor. When the strength of capital relative to labor increases, wages tend to fall. The converse is true: when the strength of labor relative to capital increases, labor is able to secure a larger fraction of profits. Also, the counter-factual scenario described above does make clear that a genuinely egalitarian and united working class would be the best scenario for the class as a whole.
But does this establish German's answer to the "who benefits?" question? I do not think that it does. Let's stick with the "monetary" interpretation of "benefit" (I'll consider other forms of "benefit" later). Is it in fact true that working class men don't draw any such benefits from the oppression of women? The answer, I think, is no: working class men do benefit from the oppression of women. Let's consider some examples. Take divorce. Studies show that the living standards of women tend, on average, to substantially drop after divorce, whereas men's living standards go up. That trend, German would surely agree, exists because we live in a society in which women are oppressed, thus the difference in monetary benefit from divorce derives from oppression. Yet men consistently come out on top, and thus benefit from it. Were arrangements to change such that men's living standards didn't go up on average after divorce, they would thereby lose a material benefit.
Now, German can reply here as follows: "but this is small potatoes compared to the benefits the ruling class garners from a sexist labor market and a sexual division of labor in the home". And she's right, as far as the claim goes. But replying in this way concedes my point: working class men do benefit, albeit in particular ways that don't mesh with their overall class interests, from the oppression of women. That's in part how sexism reproduces itself over time: some men are reluctant to give up benefits and privileges (however small, in the grand scheme of things) granted to them by sexist social relations. And this is also in part why the divide-and-conquer tactics of the ruling class are effective in some cases. After all, if the divide-and-conquer tactics didn't include some promise of a small benefit (small in comparison to the large overall gains that could be won without divisions), they wouldn't work. To say that men don't benefit at all is to lack an explanation of how the ruling class is sometimes able to successfully divide and conquer on the basis of gender oppression.
Think of it this way. Suppose that a sexist male worker has a balance sheet that adds up all of the relevant benefits and costs that pertain to his status. I agree, along with German, that there should be a large red entry in the "costs" column that makes clear what the worker is losing as a result of living in a capitalist society in which the working class is divided, and thus more easily conquered, by capital. But that doesn't mean that there aren't going to be any small green entries in the "benefit" column. Though they will be canceled out by the large red entry in "costs" column, there are still going to be entries in the "benefit" column.
Or take this example of benefiting from sexism. Imagine a household in which a married man and woman, both employed and both working class, abide by a traditional sexist division of labor at home. The woman works what we might call a "double day", that is, she puts in her paid 40 hrs a week at work, but returns home do her second shift of hard domestic labor for no pay. Suppose she is hard at work washing dishes while her husband relaxes on the couch and reads a stimulating novel. Would we really say that the man isn't benefiting from this sexist division of labor? To be sure, we can imagine a world that was better for both the man and the woman in which domestic labor wasn't privatized and unpaid, but socialized and equitably distributed. This arrangement would grant both parties greater benefits than they (respectively) receive in the status quo. But though this arrangement is a surely goal worth fighting for, it's a counter-factual scenario. The "who benefits?" question, however, pertains to the actual world. And in the sexist world we actually live in, the man on the couch is befitting in the short term, since he enjoys the fruits of his wife's labor while he reclines and reads.
And there are still other examples of benefits. For instance, in a sexist labor market, individual male workers benefit from having more job options available to them. Moreover, they benefit, as individual male workers, from their ability to more easily get promoted, get raises, etc. in the workplace. These benefits are real, material facts about our society. To be sure, qua worker, it is not in the overall class interest of male workers to exclude and subordinate any other members of their class. Each member of the working class is stronger when the class as a whole is stronger. From the narrow perspective of earnings, sexist working class men stand to benefit much more from united working class action than they do from the status quo. But that doesn't mean that men don't, in the mean time, gather various monetary benefits from living in a sexist society. Even though capital benefits long-term from sexism in a way that workers don't, it doesn't follow that no working class men benefit from it. Beyond being false, this claim creates confusion and has the potential to alienate left-wing allies who are drawn to socialist (and, in particular, Marxist) politics in a time of economic crisis.
So, I think the socialist Left can do without the "working men don't benefit from sexism" claim. First off, even from the perspective of monetary benefits, we've seen that the claim is false. Second, when we broaden the meaning of "benefit" the claim is even less plausible. There are innumerable examples here, but think, for instance, of the way that many young girls are socialized to be less confident in answering questions in a math class, whereas boys are socialized to think they should always "speak up" and answer such questions confidently. That isn't straight-forwardly monetary, but it is a benefit that boys enjoy (whether they want to or not) because of sexist gender norms in the socialization process. Saying that men don't benefit at all obscures these facts.
Still, socialists have extremely valuable, indeed essential, points to make in these discussions. It is true that the question "who benefits?" requires an answer that is class-specific. Saying "men as a whole benefit" is imprecise- since men of different classes may benefit in different ways (or, in some cases, some men may not benefit at all). Moreover, it also needs to be said that not every form of womens' oppression generates a direct benefit to men. Take "beauty" norms. Women are pressured to comply with oppressive norms that specify how they are to dress, what they are to look like, etc. Moreover, these norms pressure women into buying all sorts of expensive products, chemicals, etc. in order to live up to the standards placed before them. But, although men don't have to deal with this particular load of shit, they aren't really benefiting from the fact that women do have to deal with it. They are off the hook, sure. But that's more of a "negative" benefit than a positive one. It's not as though mens lives are better because women are forced to comply with all of these oppressive norms. To be sure, mens lives would be worse if they were similarly forced to comply. But just because something would be worse, it doesn't follow that I benefit from not enduring it. I wouldn't say that I benefit from the fact that I'm not being electrocuted right now. It is, to be sure, a privilege not to be oppressed in some particular way. But having the privilege of not being oppressed is not the same as directly benefiting from the continued existence of a form of oppression. This distinction is important. Sometimes this sort of privilege overlaps with certain benefits, but I would wager that it doesn't always overlap.
What, I think, motivates arguments like that put forward by German is the worry that if one admits that working class men benefit from sexism, one must admit that the working class is too fractured and divided to be capable of uniting to fight the ruling class. But that's not so. The idea that it is impossible for the working class to unite emerges from other sources (e.g. for an influential statement of the impossibility claim see Laclau and Mouffe's arguments in favor of this thesis in their Hegemony and Socialist Strategy). Drawing attention to the ways in which some sections of the working class derive benefits from oppressing other workers does not undermine the possibility of working class unity. Nor does it commit us to controversial concepts like the "labor aristocracy" or the like. On the contrary, such a critique of schisms among working class people is a necessary precondition to working class solidarity. Solidarity is an egalitarian idea that presupposes relations of equality and respect; there cannot be solidarity between two groups when one is actively involved in the oppression of another. Socialists have long realized this, and the history of the socialist Left is filled with interventions by Marxists arguing against racism, sexism and other forms of oppression from within the ranks of the labor movement.
Finally, the socialist counter-factual claim discussed above is powerful and can't be re-stated enough: if things were to radically change and the working class did overcome its internal divisions and inequalities... there would be no difficulty in bringing the basic structure of our society under democratic, community control in order to service human needs rather than profit. It is only the basis of having built such a working-class movement that we can really talk about building a socialist society, that is, an egalitarian society based on freedom, equality and solidarity. Any politics that promises full liberation without overcoming the domination of the ruling class is complicit in the continued domination of human beings by the iron laws of profit.
[Postscript: There is also a further complication here that concerns the notion of "benefit". In one sense, "benefit" is analogous to "good for someone". "Good for", of course, could be read (in an Aristotelian spirit) as "conducive to one's flourishing or well-being". Now, upon reflection, few of us would want to say that it is good for someone to oppress another. While they might acquire certain material privileges by means of oppression, they would nonetheless fall short of flourishing. Being oppressive is not a character trait we would associate with flourishing or living well; on the contrary, we understand such behavior to be a vice, something that evinces internal obstacles to flourishing. So, in this sense, we could say that men don't benefit from sexism since it is not good for them to be oppressors. It would be better, even from the perspective of their own well-being, if they weren't oppressive but rather more disposed to want to stand in relations of equality vis-a-vis women. This, of course, probably isn't the interpretation of "benefit" most people have in mind when they discuss the "who benefits?" question.]