When you come down to it, poverty is about not having control, and wealth is about having it.
Poor people are subject to the vicissitudes of life. They don’t have a buffer. Each negative shock, large or small—getting sick, having your hours reduced at work (or losing your job altogether), having your car or refrigerator break down—is a crisis. It’s hard to plan ahead and life is ruled by events beyond one’s control.
Rich people have as much control as the unalterable facts of life allow. They can’t eliminate illness, but they can minimize the risk, finance the best possible care, and have plenty of resources to tide them over until they are on their feet again. Their standard of living is immune to the short run ups and downs of money-making, and everything they own can be replaced. Their span of control can extend beyond their own consumption to include charities, foundations, civic organizations, and even political parties.
Economists assume that the sole motive for economic life is consumption. In the standard formulation, wealth is a transitory condition whose purpose is to enable future consumption (income smoothing) or, at most, to confer the consumption-like benefits of the bequest motive. Control as such plays no role. Similarly, it doesn't matter for a poor person whether they finance a good, like health care, out of their own savings or if it’s provided by a public program like Medicaid. Whether they can control their access is irrelevant.
I’m not a psychologist, but my understanding of the research literature is that a sense of control is essential to well-being. In a market economy, wealth is the basis for control.
Now it’s true that a program like Medicaid, by spelling out as explicitly as possible the rights of beneficiaries, can confer a form of control: if you've been denied a benefit, you can invoke your rights and hold the government to its obligations. This is a matter of degree: how the rights are defined, how accessible the appeal system is, how fairly it operates. For most people, a well-designed public program that minimizes capriciousness and error is a more promising vehicle for control than out-of-reach wealth. But if you've got it, wealth is better.
This is why rich people, in general, oppose the use of taxes that would take their money and purchase such things as health, a cleaner environment, or education. They aren't against these things—far from it. They are happy not only to pay their own bills but also make donations to hospitals, universities or the Nature Conservancy. But the question is, who controls how the money is spent and who gets the benefits? The whole point of wealth is to have that control. If you were rich and cared only about your own consumption, you could give most of it away, even as taxes.
Politically, what I’m saying is that egalitarians should be in favor of not only more equality of consumption, but also more equality of control.