Why do we respond to ‘thanks’ with “you’re welcome”?

We all know that politeness and good manners go a long way in how we are perceived. Ever since childhood, we have been taught the fundamentals of good manners: please, thank you, sorry, you’re welcome and other greetings. But have you ever stopped and wondered why they are a part of common courtesy and what is the meaning and significance behind them? Here is the origin and history behind one of the most common phrases of politeness, “you’re welcome.”  

Where does the phrase “you’re welcome” stem from? 
According to language experts, this ubiquitous saying is derived from the Old English word “wilcuma.” This ancient word fused together the two ideas of “pleasure” and “guest.” Essentially, it was used by hosts to express their openness and gratitude to their guests and visitors. It became more popular in the early 1600s when used in Shakespeare’s famous play titled “Othello” as a reflexive response to another popular phrase, “thank you.” Since then, it was accepted in normal speech and conversation that these two phrases complement each other. The reciprocity which emerged from them was a part of courtesy and politeness. 

In today’s day and age, it follows the purpose of assuring someone that they are not under the obligation of repaying you. Other popular replacements for the saying include: m 

My pleasure, no worries, no problem, happy to help, etc, with all of them having the same connotations. 

An interesting anecdote about the importance of this phrase 
Post-World War II, the Allied Nations of Europe suffered great losses. In order to extend aid to them, the United States sent a train filled with food items, clothing and other necessities. These products were loaded onto a ship and then distributed in Italy, France, UK and other nations. However, in this gesture, there was an element of portraying. The fact that these were American goods was made clear with patriotic hoardings and flags in the European nations.  

The following year, as an expression of gratitude, the European countries, too, sent some goods to America. To this, America considered returning the favour again. It did not happen, but even the consideration of it was a nod to this compulsive pattern of returning favours so that one party does not owe the other anything. In such situations, the importance of the phrase “you’re welcome” is understood clearly as it functions as the last word.