What does "There is no such thing as a free lunch" mean?

Solution 1:

The meaning refers to the fact that there is nothing for free, everything has a more or less evident cost.

The is no such a thing as a free lunch:

• The economic theory, and also the lay opinion, that whatever goods and services are provided, they must be paid for by someone - that is, you don't get something for nothing. The phrase is also known by the acronym of 'there ain't no such thing as a free lunch' - tanstaafl.

Origin

• Before discussing the origin of 'there's no such thing as a free lunch' it would be useful to go back to the days in which lunches were free. Free lunch was a commonplace term in the USA and, to a lesser extent in Britain, from the mid 19th century onward. It wasn't used to describe handouts of food to the poor and hungry though, it denoted the free food that American saloon keepers used to attract drinkers; for example, this advertisement for a Milwaukee saloon, in The Commercial Advertiser, June 1850:

At The Crescent...

Can be found the choicest of Segars, Wines and Liquors...

N. B. - A free lunch every day at 11 o'clock will be served up.

Free lunches,

• often cold food but sometimes quite elaborate affairs, were provided for anyone who bought drink....... Indeed, some saloon keepers were prosecuted for false advertising of free lunch as customers couldn't partake of it without first paying money to the saloon.

The concept was elaborated later into an important economic theory.

• It was into this context that the economic theorists enter the fray and 'there's no such thing as a free lunch' is coined. It isn't known who coined the phrase. It certainly wasn't the economist Milton Friedman, who was much associated with the term. He was a celebrated Nobel Prize-winning economist and his monetarist theories were highly influential on the Reagan and Thatcher administrations in the 1980s and 90s. Friedman certainly believed that 'there's no such thing as a free lunch' and he published a book with that title in 1975, but wasn't, and never claimed to be, the originator of the phrase.

• The phrase appears to have come about in response to the libertarian views of Henry Wallace, the US Vice President between 1941 and 1945.

(The Phrase Finder)

Solution 2:

The idiom is less than 100 years old. The first recorded uses date back to the 1930's. There's more detail in the Wiki article

The original reads

There ain't no such thing as a free lunch.

There are variations, including

There's no free lunch in physics.

The general meaning is that everything is a trade-off; you can't get anything for nothing; getting something for nothing is a fool's (impossible) dream.

This applies to economics, physics, relationships - everything.

A close cousin expression goes

If something seems too good to be true, it probably is.

Do not be discouraged.

Solution 3:

The saying "There's no free lunch," as I understand it, refers primarily to hidden costs. I believe it's commonly used in situations where people think they're getting something for free.

For example, imagine someone screaming "Hooray! I just won a prize - a free car!"

Someone else might reply, "There's no such thing as a free lunch," advising the winner to read the fine print. Will they have to pay taxes on the car? Will they have to buy insurance for it? Are there other hidden costs they need to be aware of?

The phrase doesn't have to be restricted to economics. For example, imagine someone building a resort on a remote, beautiful beach. They think it's the perfect gig, but they may actually miss certain things back in the city. Moreover, tourists who visit the resort will make the beach a little less remote and a bit more polluted.

On a bit of a tangent, I found this statement intriguing: "Campbell McConnell writes that the idea is 'at the core of economics.'" I've long said that "There's no free lunch" is the fundamental law of economics. In other words, you can't create wealth out of nothing.

In that spirit, one could loosely use "There's no free lunch" as a corollary of the basic scientific maxim that matter can neither be created nor destroyed. Instead of writing all those complex mathematical formulas, Einstein could have just said "There's no free lunch."

(I just discovered that the Wikipedia article I linked to mentions the science link... "In the sciences, TANSTAAFL means that the universe as a whole is ultimately a closed system.")

Wikipedia's article There ain't no such thing as a free lunch has some information on the origin of the phrase.