Because PRE (one of several scholarly journals coming out of the American Physical Society) publishes papers like the one covered in this Fox News story and this CNN/Money story about how physics methods can help figure out where you should locate you new shoe store, grocery, haberdashery, or pet store.
Pablo Jensen of the Ecole Normal Superiure in Lyon, France plugs data into a model that evaluates the quality of various locations in a city for different types of businesses. He can turn the numerical crank of his equations and tell you whether a bakery might flourish on one corner or do better on another.
So how is this physics instead of economics? Well, Jensen modeled businesses in the same way physicists model atoms interacting with each other. He found that just as two atoms may sometimes attract or repel each other, depending on things like their magnetic fields, businesses can seem to attract or repel each other. A shoe shop could do well next to a formal wear outlet, but you might not want to loiter at a sidewalk cafe that’s next door to an open air fishmarket.
You can read the abstract for Jensen’s paper online, but the Fox and CNN/Money stories seem to cover it pretty well.