The most famous living utilitarian/hedonist philosopher, Peter Singer, has during the last few years been heavily engaged in the effective altruism movement, and his book The Life you Can Save has been followed by a website (and organization) with the same name. Effective altruism focuses on the voluntary giving of money to charities that are “approved” because of their effectiveness in reducing suffering in the world. On the site The Life you Can Save people are urged to take a pledge to donate at least 1% of their income to charities. All this can be said to represent a turn in Singer’s thought towards relaxing utilitarian demands on people in order to get people to actually share some small part of their resources, instead of just switching off due to what they perceive are unreasonable moral demands and give nothing instead (although in theory, I assume that Singer still maintains that people in affluent countries should give much more than 1%).
It is, of course, commendable if people want to give some more (on top of taxes going to foreign aid, and the like) of their wealth to people in much poorer circumstances. I believe, however, that the effective altruism movement seems to disregard the political level too much. Advocacy for larger voluntary donations to charities must always go hand in hand with at least as much advocacy for policy changes, mainly when it comes to raising taxes (preferably progressive taxes). People often have moral principles that entail solidarity with the less fortunate; but people (including moral philosophers) are usually also aware of their own moral weakness, i.e., their propensity to neglect their duties when no one is watching, or when their friends, family, and acquaintances do not provide any social pressure to act in certain ways. Even though we know what is good and what is demanded of us, and even though we are glad to do it, we often prefer a bit of coercion to keep us on the right path. A tax can provide this; giving to charities not as much. (Of course, a tax will also make people who do not believe in altruism pay, but that is not a problem in this context, since utilitarianism is not, in principle, against such coercion.)
A further advantage with taxes rather than voluntary giving is that we can be more sure that other people are doing their fair share. Again, we often want to do good, but when we see that other people are not doing anything, we ourselves feel unjustly treated and may decide not to do anything either. Taxes, on the other hand, make sure that everyone does their fair share. If the whole point of Singer’s turn to effective altruism was to loosen moral demands in the hope that people would be willing to give a little rather than nothing, then he should also consider the bad psychological effects of feeling that others are not doing their fair share and the good psychological effects of having some (mainly self-imposed) sanctions to compel us to do what we believe is good, but are, at least sometimes, too weak-willed to do.
A last point pertaining to all this is that, at least for some purposes, taxed-based charity is more effective, in that recipients can probably rely more on a steady stream of aid. To make a parallell to unemployed people in welfare states, they would not feel secure if their benefits came very irregularly with different sums each month. It is, in other words, best if poor people can claim certain benefits as a right (which only states, or perhaps imagined libertarian state-like voluntary associations, can safeguard) rather than rely on charitable generosity. It is probably the case the total sum of charitable donations fluctuates quite a lot, depending on which disasters are covered in the media at the moment. Relying on tax-funded aid, managed by state agencies, probably avoids these fluctuations to a larger degree than voluntary donations.