The concept of tip-based wages is perfectly sound.

As a waiter, the more you can sell a customer, and therefore benefit your employer, the more you stand to make for yourself. As a delivery driver, the faster you can accomplish your tasks, and therefore contribute to efficiency, the greater volume of tips you stand to pull in. And, theoretically, any performance above the expectations of the customer will be rewarded in gratuity. Shoddy employees are quickly weeded out, good ones earn from the sweat of their brow, the tertiary sector of the economy functions smoothly, and everybody is happy.

All of this, of course, is predicated upon the presumption that consumers understand that the tip is part of the expense for services rendered. Our legislators are clearly operating under such a presumption; why else would the minimum wage for tip-earners in Iowa be set at $4.35 per hour when everybody else is guaranteed $7.25 per hour?

Yes, tip-based wages are for the real go-getters, the hard workers and the sturdy self-starters — the kind of people with the stones to see their work ethic directly monetized.

In Western Europe, and non-American cultures generally, tip amounts are not left to the discretion of the consumer; they are automatically factored into the bill. That is to say, the prices on the menu include a percentage that is paid to the server in lieu of a tip. Were you to dine in Germany, for example, you would swipe your credit card, pay the number printed on the receipt, sign your name and be on your merry way.

But you are not in Berlin, you are in Ames. So when the waiter or bartender or delivery person slides you that receipt that says “Merchant Copy,” and you draw a line through the space marked “Tip,” you have just shirked paying for part of the expense of your luxury.

A few years ago, I worked as a pizza delivery driver in Iowa City, and I was delivering a $10 pizza to a dormitory. I arrived in less than the quoted delivery time with a delicious, hot pepperoni pizza and met the customer on the steps of her building. As we exchanged money for goods, she smiled and politely said, “Sorry, I can’t tip you, I only had enough money for the pizza,” and then handed me exact change. As she said that, I thought, “No problem, I’ll just pay my rent with your good intentions.”

I couldn’t say it then, but I can say it now: If you can’t afford the tip, you can’t afford the product. The mere fact that you are prompted to pay someone a tip means that whatever you are purchasing is a luxury item.

It falls upon you, the consumer, to behave like a decent person and pay the full cost of what you bought. I’m not asking that you be charitable; as you recall, the government is counting on you to offset that extra-low wage your waiter is making. They expect you to conform with an obvious societal norm and pay the additional 15 percent.

You certainly don’t have to, though. You won’t be kicked out of the bar or blacklisted by your favorite pizza joint for tip-shirking, but you will be leeching off the labor of a member of your community; and having read this far, you will be doing so consciously. Keep this in mind the next time you’re filling out a receipt.