Walter Williams‘ latest column distinguishes between “price” and “cost,” while explaining the negative impact of taxes on otherwise mutually beneficial transactions.

Suppose you buy a gallon of gas for $3. How much did it cost you? You say, “Williams, that’s a silly question. It cost $3.” That’s where you’re mistaken, because there’s a difference between price and cost. To prove that price and cost are not the same, consider the following. Suppose you live and work in New York City and routinely pay $15 for a haircut. Imagine you were told that there’s a barber in Boise, Idaho, who can give you the identical haircut for just $5. Would you start going to the Boise barber? I’m betting you’d answer no because even though the price is cheaper, the cost is greater.

We might think of price as the money that’s actually given in exchange for the transfer of ownership. When you purchased the gallon of gas, you simply transferred your ownership of $3. What the gas cost you is a different matter. One way to determine the cost of a gallon of gas is to ask yourself what sacrifice you had to make in order to have $3 to buy it. Say that your annual salary is $75,000. Your total federal income tax, state income tax, local taxes and Social Security and Medicare taxes come to about 35 percent of your salary. That means that in order to purchase the $3 gallon of gas required that you earned about $4.60 in order to have $3 after taxes. That means a gallon of gas costs you $4.60 worth of sacrifice. But that’s not so costly as it is to a richer person — for example, someone earning a yearly salary of $500,000. He has to earn more than $5 before taxes in order to have $3 after taxes to purchase gas.

If taxes only concealed hidden costs of what we buy, we’d be lucky, but taxes are destructive in another hidden way. Suppose I want to hire you to repair my computer. Having the work done is worth $200 to me, and performing the work is worth $200 to you. The transaction occurs because we have a meeting of the minds. Suppose Congress imposes a 30 percent income tax on you. That means that if you repaired my computer, you would receive not $200, what it was worth to you to do the job, but instead $140 after taxes. You might say the heck with repairing my computer; spending time with your family is worth more than $140.

You might then offer that you’d do the job if I paid you $283. That way, your after-tax earnings would be $200 — what doing the job is worth to you. There’s a problem. The repair job was worth $200 to me, not $283. So it’s my turn to say the heck with it.