An upscale grocery store chain $($similar to Whole Foods$)$ hired an economist to figure out which location$-$related factors best predict sales success, such as neighborhood income, neighborhood education, traffic patterns, proximity to other kinds of stores, etc. He found$$and I am NOT making this up$$that the single best predictor of sales was proximity to a bowling alley. In other words, for an upscale grocery store, sales increase the farther away from a bowling alley it is located. The capacity to calculate the precise effects of location on sales is an example of which of the following segmentation criteria?