*Originally posted on Notes On Liberty*

In economics, there are two types of numbers that we use. Cardinal numbers express amounts. For example, “one”, “two”, “three”, etc. are all cardinal numbers. You can add them, subtract them, or even take them to an exponent.

Money prices are cardinal, which is why you can calculate precise profits and loss.

On the other hand, ordinal numbers express ranks. For example “first, “second”, “third”, etc. are all ordinal numbers. It doesn’t really make sense to talk about adding (or subtracting or exponentiating) ranks.

Almost all economists believe that utility is ordinal. This means your preferences are ranked: first most preferred, second most preferred, and so on. Here is a made up value scale: Continue reading “The Economics of Hard Choices”