This column by Steven Landsburg is a good demonstration of why so much economic commentary is so bad. Landburg sets out to demonstrate that turning off life support for patients who can't pay for it is a good idea:

Tirhas Habtegiris, a 27-year-old terminal cancer patient at Baylor Regional Medical Center in Plano, Texas, was removed from her ventilator last month because she couldn't pay her medical bills. The hospital gave Ms. Habtegiris' family 10 days' notice, and then, with the bills still unpaid, withdrew her life support on the 11th day. It took Ms. Habtegiris about 15 minutes to die.

Bloggers, most prominently "YucatanMan" at Daily Kos, are appalled because "economic considerations," as opposed to what the bloggers call "compassion," drove the decision to unplug Ms. Habtegiris. I conclude that YucatanMan either doesn't understand what an economic consideration is or doesn't understand what compassion is, because in fact the two are not in conflict.

Bold words; you'd think from reading them that Landsburg would follow them up with an airtight case for his proposition. But, no: the main point of Landsberg's argument is that, if asked at the right occasion, poor people would not choose to guarantee that they are kept on life support:

The back of my envelope says that a lifetime's worth of ventilator insurance costs somewhere around $75. I'm going to hazard a guess that if, on her 21st birthday, you'd asked Tirhas Habtegiris to select her own $75 present, she wouldn't have asked for ventilator insurance. She might have picked $75 worth of groceries; she might have picked a new pair of shoes; she might have picked a few CDs, but not ventilator insurance.

No evidence whatsoever is presented for this (and the back of the envelope calculation seems to be off anyway). Landsburg's argument is based entirely on his own prejudices.

What pisses me off though is not Landsburg argument or his column per se. What pisses me off is that Landsburg presents a strong version of this thesis up front ("I conclude that YucatanMan either doesn't understand what an economic consideration is or doesn't understand what compassion is" ) and then follows it up with an argument that crucially depends on missing facts. Its downright dishonest, and unfortunately it is also the pattern in so much of economic commentary. A bold claim is followed up by a justification that depends on a host of assumptions.

There are others problems as well. It is not true that we help the poor once on their 21st birthday; we help them continuously. There is no reason to apportion aid based on someones preferences at their 21st birthday, rather than someone's current preferences. The choice Landsburg presents - what form would aid take if all of it was given on a person's 21st birthday - is a false one, since aid is given continuously throughout a person's life, and there is no reason why it cannot be adjusted to the evolving desires of that person.