In most countries, the practice of tipping remains more of a custom than a mandate. In fact, there are entire organizations dedicated to the complete eradication of tipping, which they say compels the public to compensate for the low wages paid by greedy or stingy employers. Nevertheless, tipping has become a very common practice when dealing with those in the service or hospitality trade. But why are we expected to tip certain professionals, such as waiters or valet parking attendants, but not others, such as desk clerks and chefs? There are a number of things to consider when it comes to the seemingly arbitrary practice of tipping.

One reason we tip certain service employees such as waiters or bellhops is to help compensate for a gap in wages. Employers are legally permitted to pay less than minimum wage to certain employees who routinely benefit from tipping. This means a waiter may only receive a few dollars an hour as a regular salary from the restaurant, so the difference must be made up in tips. A waiter may also be responsible for tipping other employees such as bussers and bartenders. Without regular tips, waiters and barmaids may not even earn the legal minimum wage.

However, other employees of the same restaurant are rarely tipped. Cooks, hosts and dishwashers are generally paid at least the minimum hourly wage for their services. Their job responsibilities are the same regardless of the volume of business. Tipping a cook or dishwasher may seem counter-intuitive to most diners, since there is little personal interaction and those kitchen personnel appear to be properly compensated already. Waiters and waitresses may have to compete for part-time hours, while cooks and other kitchen staff are usually guaranteed full-time work or even overtime.

Tipping is also more likely to occur whenever the employee performs above and beyond the call of duty. A hotel desk clerk is only performing his or her duty during the check-in process, but a bellhop may carry several large suitcases directly to a customer's room and offer to fill the ice bucket or demonstrate the room's amenities. Many people equate the practice of tipping with rewarding good service. By tipping the bellhop or concierge well, the customer may receive even better treatment on a return visit.

Sometimes the decision between tipping and not tipping is a matter of perception. Some customers of a family-owned restaurant, for example, may not tip the owner of the establishment if he or she waits on their table, but will tip a hired waiter. The idea is that the owner of the restaurant is already well compensated through total sales, but the hired waiter still depends on tipping to earn a decent living wage. The owner of a hair salon may earn a decent salary through product sales and specialized services, but individual stylists who rent booths may rely more on tipping to earn a living wage.

Some experts speculate that tipping is also a form of social equalization, a means to share the wealth with a hardworking but underpaid service worker. The practice of tipping used to be connected to the perceived quality of services provided, but in modern times tipping has become almost ritualistic. Regardless of the actual quality of the service, many customers realize that service and hospitality workers do work extremely hard for relatively low wages. One reason we tip certain professions and not others is because of this perception. It simply makes us feel better knowing we can reward others for their service and attention.