Ed Glaeser has a good post, The Moral Heart of Economics, on the underlying ethical theories of economics. Tyler and I also discuss this isssue in our chapter on ethics in Modern Principles.

Even though the predictions of economics are independent of any ethical theory, there are ethical ideas behind normative economic reasoning. An economist who rejects the idea of exploitation in kidney purchases, for example, is treating the seller of kidneys with respect–as a person who is capable of choosing for himself or herself even in difficult circumstances.

Similarly, economists don’t second-guess people’s preferences very much. If people like wrestling more than opera, then so be it; the economist, acting as economist, does not regard some preferences as better than others. In normative terms, economists once again tend to respect people’s choices.

Respect for people’s preferences and choices leads naturally toward respect for trade–a key action that people take to make themselves better off. As we saw in Chapter 9 on externalities, economists recognize that trade can sometimes make the people who do not trade worse off. Nonetheless, the basic idea that people can make decisions and know their own preferences leads economists to be very sympathetic to the idea of noncoercive trade.

Economists also tend to treat all market demands equally, no matter which person they come from. Whether you are white or black, male or female, quiet or talkative, American or Belgian, your consumer and producer surplus count for the same in an economic assessment of a policy choice.

None of this it to say that economists are always right in their ethical assumptions. As we warned you in the beginning, this chapter has more questions than answers. But the ethical views of economists–respect for individual choice and preference, support for voluntary trade, and equality of treatment–are all ethical views with considerable grounding and support in a wide variety of ethical and religious traditions.

Perhaps you have heard that Thomas Carlyle, the Victorian-era writer, called economics the “dismal science.” What you may not know is that Carlyle was a defender of slavery and he was attacking the ethical views of economics. Economists like John Stuart Mill thought that all people were able to make rational choices, that trade not coercion was the best route to wealth, and that everyone should be counted equally, regardless of race. As a result, Mill and the laissez-faire economists of the nineteeth century opposed slavery, believing that everyone was entitled to liberty. It was these ethical views that Carlyle found dismal. We beg to differ.