Yesterday I wrote about the idea of scientific versus political numbers. Scientific numbers are those that we rely on for decision-making. They are not always better and more accurate numbers than political numbers, but they are generally based on some sort of standardized methodology and have a concrete and agreed upon backing to them. Political numbers are more or less guestimates or are formed from sources that are not confirmed to be reliable. While they can end up being more accurate than scientific figures they are harder to accept and justify in decision-making processes. In the end, the default is scientific numbers, but scientific numbers do have a flaw that keeps them from ever becoming what they proport to be. How do we know when it is time to stop counting and when we are ready to move forward with a scientific number rather than fall back on a political number?
Christopher Jencks explores this idea in his book The Homeless by looking at a survey conducted by Martha Burt at the Urban Institute. Jencks writes, “Burt’s survey provides quite a good picture of the visible homeless. It does not tell us much about those who avoid shelters, soup kitchens, and the company of other homeless individuals. I doubt that such people are numerous, but I can see no way of proving this. It is hard enough finding the proverbial needle in a haystack. It is far harder to prove that a haystack contains no more needles.” The quote shows that Burt’s survey was good at identifying the visibly homeless people, but that at some point in the survey a decision was made to stop attempting to count the less visibly homeless. It is entirely reasonable to stop counting at a certain point, as Jencks mentions it is hard to prove there are no more needles left to count, but that always means there will be a measure of uncertainty with your counting and results. Your numbers will always come with a margin of error because there is almost no way to be certain that you didn’t miss something.
Where we chose to stop counting can influence whether we should consider our numbers to be scientific numbers or political numbers. I would argue that the decision for where to stop our count is both a scientific and a political decision itself. We can make political decisions to stop counting in a way that deliberately excludes hard to count populations. Alternatively, we can continue our search to expand the count and change the end results of our search. Choosing how scientifically accurate to be with our count is still a political decision at some level.
However, choosing to stop counting can also be a rational and economic decision. We may have limited funding and resources for our counting, and be forced to stop at a reasonable point that allows us to make scientifically appropriate estimates about the remaining uncounted population. Diminishing marginal returns to our counting efforts also means at a certain point we are putting in far more effort into counting relative to the benefit of counting one more item for any given survey. This demonstrates how our numbers can be based on scientific or political motivations, or both. These are all important considerations for us whether we are the counter or studying the results of the counting. Where we chose to stop matters, and because we likely can’t prove we have found every needle in the haystack, and that no more needles exist. No matter what, we will have to face the reality that the numbers we get are not perfect, no matter how scientific we try to make them.