It does become easier to focus on situations in which imminent death is anticipated and possibly observable. Think of the resources and attention devoted to the exoneration of death row inmates as they near execution, versus the attention given to them in the years/decades leading up to the execution. Nevermind the many, many more people who may be unjustly sentenced to life imprisonment.

It is not a new thing. In Seneca's "On the Shortness of Life" there is about people praying to get a few more years of life, while wasting decades when they were younger.

For me it seems as some sort of artefact of human cognition. (Mercilessly used by "last minute" opportunities by salesmen... and journalist.)

Human empathy is an instinct developed on rought evolutionary heurestics, is not rational and doesn't fit complexities of modern world. What else is new?

This particular cognitive bias is formally known as the ...

https://en.wikipedia.org/wiki/Identifiable_victim_effect

12 kids and 1 adult trapped in a cave is a discrete, solvable problem. Millions of kids in poverty much less so.

We're much better at dealing with time-bounded, localizable problems.

Stalin's quote about tragedies and statistics comes to mind.

I was wondering which quote you were talking about. I found "A Single Death is a Tragedy; a Million Deaths is a Statistic".

There as Quote Investigator article on it, it is again a much older quote. https://quoteinvestigator.com/2010/05/21/death-statistic/

Still, the question is: for a given amount of resources (time, money, people) how many quality-life-years can be added?

If this quality is order of magnitude lower than other less exciting solutions (e.g. access to medicine and education for kids from poor families), then we should be aware that what we pay for is not lives saved, but an emotional entertainment show.

I'm reminded of a fellow in, IIRC, St. Louis. He expends tremendous amounts of energy, time, and money rescuing stray dogs, to the point where he doesn't have much of a social life. It's all about the dogs.

Someone asked him why he didn't instead pour that energy into helping homeless people. His response was something to the effect that there were plenty of others helping people; his passion was the dogs. I believe he also turned the question around: what are you doing to help the homeless?

A few dozen cave divers can't do much to help the millions of impoverished children, but they used their skills to perform heroic and deadly feats to help 12 children and their coach, and inspired many around the world to ask themselves these types of questions.

Reducing that to a cost-benefit analysis vs some vague "but can't we spend that effort on the other lost kids?" question is both impossible and missing the point.

It's hard to imagine leaving them in there AND living with the knowledge that they had been left in there. Attempting a rescue seems like a pretty human thing to do, and I found it hard to blame people for being people. I certainly do awesome & dumb things because I'm a person.

The difference is one is a very abstract and broad problem while the other is a very concentrated and narrow one. Humans have a hard time in the abstract. I do admit that the sensationalism of this event brought focus from the world but the same rules apply to someone who's stuck in a burning building or under a car or whatever, people will go out of their way to help when there's a well defined and immediate problem.

How much did this rescue mission cost?

1 human life

and US$3m

Do you have a source for that number? It seems incredibly low.

It is an interview in Thai with the guy who was sponsoring the water pumps.

So it was $3M paid for by a rich guy? Was he going to donate the money to charity if he didn't spend it on this?

I do not know the answer of this question.

Most of the money and equipment were donated.

While it may be true, not really the point GP was getting after.

Cost or donation, can we expect the same for every child in need?

[0] is the first source that popped up on a quick googling; the US alone spent 18 billion dollars between 2002 and 2014 on food aid (to hungry children and such).

[0] http://www.humanosphere.org/world-politics/2014/10/united-st...

Can we expect 1 person to sacrifice their life for every 13 children in need?

Helping every child in poverty requires a long term paced effort rather than a one time heroic one. As inspiring as this rescue was, it doesn't scale.

Especially in a place like Thailand where there is a lot of real poverty still.

What do you mean? The OP question is straightforward. How can you twist the meaning that much is beyond me