Jargon Du Jour - Constant Returns to Scale (CRS)

Constant Returns to Scale: in a production function, it is when you increase your inputs by some amount m, then output increases by exactly m. It implies that a prdoucer would be just as efficent producing a small number of goods as they would be producing a large number of goods.

CRS is a common underlying assumption of many economic models, even if it is not a realistic one. For example,  if you have an industry that takes advantage of economies of scale then you would have increasing returns to scale. If however you are in an industry that has diseconomies of scale, then you would have decreasing returns to scale.