Running Models

Last week as we discussed models, I was reminded of the models used in equating running performances. 

I recently ran my first marathon, and as the race approached, I encountered an issue: How should I pace a distance I had never run before? I had no idea.

Marathon equivalency calculators attempt to predict race time by taking into account a previous race time and applying a formula (most often the Riegel formula). These calculators simplify the calculus, ignoring factors that can contribute significantly to running time-- elevation, slope grade, terrain, temperature-- as well as less obvious factors such an athlete's sleep or fueling. Like running models, economic models frequently rely on historical data to make predictions about the future or examine an issue on a smaller scale and then extrapolate to a larger one. Just as it would be detrimental to race a marathon during training just to learn your race pace, it is often unfeasible to measure economic effects on a macro scale. Instead, economists may focus on individual localities and then extrapolate. In both situations, the model acts as a tool rather than any guarantee, and it is expected that the real world will deviate from prediction when inherently unpredictable outside factors take effect.