Positive and normative statements

The Economics A specification is filled with interesting topics like the distinction between positive and normative statements. You probably expect me to go on about the importance of the ability to distinguish between facts and opinions, and although I find this extremely important, I will not. What fascinates me the most, actually, are positive statements. Would you not agree with me that forecasts are positive statements in their very nature? Positive statements can be either proved or disproved – or maybe you can be partially wrong or right. This raises the question: are forecasts evaluated once their time-frame is in the past? I now for a fact the National Bureau of Statistics (NBS) does evaluate, and I would expect every institution in the business of prognosis to evaluate their forecasts on a regular basis, if only to improve their reliability. To calibrate so to say.

I appreciate when forecasts are covered in the news, some attention is paid to the assumptions made to arrive at the forecast. I think this could contribute to thinking in scenarios. The computational power available to us nowadays, allows us to compute different scenarios, thus facilitating what-if-thinking. Evaluating forecasts in public could help us to understand the merit of forecasts better, and to appreciate the added-value of feedback cycles.

How can I use this in my lesson?

You could evaluate forecasts yourself with your students. You will need a forecast on the current time-frame and then collect data to either prove or disprove it. Or you can use an NBS projection. I found the National Population Projections1 of the NBS useful, since these include a comparison to the previous projections, with an evaluation of any differences.

  1. I think population is a basic economic concept, since it is made up of the mouths that need feeding and the bodies that need shelter.