Evolution of the standard description of money

I took Econ 101 Macro in the mid-1970s, in the midst of the Great Inflation. At the time, the identifying characteristics of money were still presented as

• medium of exchange
• store of value, and
• standard of value

The first of these identifies money as something we use and accept as payment. The second says the value of money doesn't change, or doesn't change much. So that if you don't spend a dollar today, it will have approximately the same purchasing power tomorrow or next week or next year. The third is how we identify money in words: "the dollar" for example.

Today the definition of money is slightly different. According to Merriam-Webster, money is defined as

something generally accepted as a medium of exchange, a measure of value, or a means of payment

The first of these is unchanged since the 1970s. And the third is rephrased but retains essentially the same meaning. The second, however, is different. No longer a reliable store of value, money is now a "measure" of value.

A "measure" of value rather than a "store" of value, because we now acknowledge that the value of the dollar changes. We now acknowledge inflation.

Is this change an improvement? I say no, it is not. It is good of course to to be honest with ourselves and admit that inflation changes the value of the dollar. But look at this graph from Robert Sahr:

The graph shows that relative price stability was possible over the long term, at least until the Great Depression. This being the case, it is wise to admit that the dollar is no longer the good store of value that it once was. But it is foolish to change the definition of money.

It would be better to hold to the old definition, and admit there is some problem with the "store of value" characteristic of money. That characteristic has changed, yes. But the problem is not that our definition went bad. The problem is that there is something wrong with the economy. A good solution would be to figure out what went wrong before it's too late. It isn't quite as simple as "printing money causes inflation".