Preferred method of measuring preference (and how to measure it, preferrably)

I was recently presented with an interesting problem. If a policy states that a particular method is preferred over all others, what would a metric to measure compliance look like?

I have been teaching Decision Support Systems for 6 years now and, academically, this is what my students call these days a "no-brainer". If preference implies that we want something maximized (e.g. money), then 51 dollars is preferred to 49 dollars, because 51 > 49. If the preference implies minimization (e.g. our tax rate), then 49% is preferred to 51%, because 49 < 51 (or, more accurately -49 > -51). This would be like the "popular vote" in a two-candidate election expressing the preference of the voters.

So I put my explanation in writing, with what I thought was a useful link to Wikipedia, rather than an overly academic reference to "Rational Choice" by Itzhak Gilboa (for instance). Big mistake. Turns out that practitioners are very suspicious of anything from Wikipedia and, by association, anything that agrees with it. So, what I thought should have been a slam dunk turned into an all-out  squirrel chase.

That gave me time to pause. Was my explanation wrong?

Sometimes, in math, in trying to explain something that we think is very obvious, we complicate things more.

As it turns out, it depends. If we consider the practitioners' side, this whole model depends on how it is implemented.

Philosophically, the model depends on knowing what constitutes preference and what the domain of choices is (the consumption set, in decision science-speak).  So, to fully develop the metric, we must define:

• How is preference demonstrated? Is it by the outcome of the decision or by including the preferred outcome in the decision process? For example, we prefer to win the lottery every week, but do we demonstrate that by winning most of the time or by buying tickets consistently?
• What are the choices? Is it a binary choice (A or B)? or is it a choice among a larger set? What does "over all others" mean? Are we lumping all the non-preferred outcomes as one single choice?
• Is this a subjective measure? If so, how is subjectivity operationalized in a way that can be detected when conducting business analysis? For example, it could be as simple as a person signing a document saying that they prefer unicorns to puppies as pets, even though the preferred choice is totally unachievable (or is it?).

As you can see, nothing is ever easy.