Can you impose pecuniary externalities upon Korean squirrels?

Look out, squirrels of the world. It turns out acorns are good for humans, too.

Here in South Korea, the popularity of acorn noodles, jelly and powder has exploded in recent years, after researchers declared the nuts a healthy “superfood” that can help fight obesity and diabetes.

In the U.S., where some Native Americans once made acorns a staple of their diet, restaurants and health-conscious blogs are starting to explore recipes for acorn crackers, acorn bread and acorn coffee.

That is bad news for squirrels and other animals that rely on oak trees for sustenance. In South Korea, where human foraging has multiplied, there are now fewer acorns on the ground, and the squirrel population has dwindled.

Is this a reductio ad absurdum of the idea that pecuniary externalities are irrelevant?  Ask your friendly neighborhood squirrel!  If you can find him, that is.  Then there is this:

Safeguarding acorns for squirrels is proving to be a tough nut to crack. That’s where the Acorn Rangers come in.

Formed at Seoul’s Yonsei University, the nascent Acorn Rangers group polices the bucolic campus, scaring off other humans from swiping squirrel food. Taking up the cause are students like Park Ji-eun, who skipped lunch on a recent day so a squirrel could eat this winter.

Strolling across campus, Ms. Park, a junior, sprung into action after spotting an acorn assailant: a woman in her early 60s, clutching a plastic bag stuffed with the tree nuts.

“The squirrels will starve!” barked Ms. Park, her voice booming so loudly that other acorn hunters—human ones—scurried away. The two argued for nearly an hour until Ms. Park emerged with the plastic bag in hand.

Here is the full WSJ story, by Dasl Yoon and Na-Young Kim, via the excellent Samir Varma.