Programs that offer airline miles as a reward are tricky because they require some assumptions about what an airline ticket is worth.
Computers can't do them because they require some minimal judgment, so human beings do them for peanuts -- say, writing a product description, for $3; or choosing the best of several photographs, for 30 cents; or deciphering handwriting, for 50 cents.
Some probably stayed home because they required mass transit to get to their depots each morning.
Some of those suffering from severe traumatic brain injuries qualify for a Purple Heart because they required medical treatment.
The top three comparables were those deemed most similar because they required the fewest adjustments.
A further 9,100 properties were reckoned to be uninhabitable because they required such major repairs.
The coal mines couldn't operate, because they required electric pumps to siphon water.
Because they required no passwords, they could be taken over with ease.
The editorial staffs couldn't be combined because they required different expertise.
Several banks were eliminated because they required higher minimums to open an account.
