“Knowing something about the monetary value and cost of the information in a measurement puts a new light on what is “measurable.” If someone says a measurement would be too expensive, we have to ask, “Compared to what?” If a measurement that would just reduce uncertainty by half costs $50,000 but the EVPI is $5,000,000, then the measurement certainly is not “too expensive.” Indeed, it would be a bargain. But if the information value is zero, then any measurement is too expensive. Some measurements might have marginal information values—say, a few thousand dollars; not enough to justify some formal effort at measurement but a bit too much just to ignore. For those measurements, I try to think of approaches that can quickly reduce a little uncertainty—say, finding a related study or making a few phone calls to a few more experts.”