Suppose there was a concern whose employees had to produce two kinds of products: widgets and squidgets. Each employee was supposed to devote about 2/5 of effort to widgets, and 2/5 of effort to squidgets, and 1/5 of effort to miscellaneous administrative tasks.

Everyone pretty much made an equal number of widgets according to a regularly scheduled plan. Some were better widgeters than others, that is true, but nobody didn't do widgets. With the squidgets, however, there was a very wide distribution in results. Some produced almost none at all; some produced them in huge quantities, sometimes several magnitudes greater than the average.

Since excellent squidgeters were also doing their share of widgeting, they would tend to work a little longer and harder. They might also have to spend their own personal money for squidget supplies and for traveling, since squidgeting often involved work outside the office. Sometimes you had to spend extra time just applying for special squidget funds, given out competitively--even though everyone, theoretically, was supposed to be squidgetting 40% of the time.

So here's the question. What would a fair weighting of widgets and squidgets look like? What would it mean to treat them equally in an evaluation process? How do we compare widgets, judged mostly on a qualtitative scale, with squidgets, where distinctions are more likely to show up as much larger differences of quantity? Is it really possible to treat them equally?

If they were really treated equally, then that would entail a huge bias in favor of squidgets. People who only produce widgets, with little or no squidgets, would be seen as only doing 60% of their jobs. Those with both squidgets and widgets would always come out ahead, even if their widgets were a little less excellent.

On the other hand, this approach would quickly lead to a complaint about "too much emphasis on squidgets." To place more weight on widgets, by the same token, would involve overvaluing small differences on a qualitative scale, in contrast to the much larger absolute differences on the squidgeting scale. One worker might have four or five squidgets in a year that someone else had zero or one.

Of course, we could have philosophical discussions about whether widgets or squidgets are really more valuable. Remember, though, that the institution already has assigned them a value of 40% each, in this particular thought-experiment. We could say that that widgets are really more important. After all--they have to get done before we even think about squidgets. But technically each worker is responsible for devoting 40% of effort to squidgets too.