Bowley's law is an observation in econometrics that the proportion of Gross National Product from labor is constant.[1] It is named for Arthur Bowley, the statistician who first observed it. It was first observed based on economic data in Britain from the late 19th and early 20th centuries.[2] Bowley's Law has long been both an empirical and theoretical point of contention between rival theories of macroeconomic (functional) distribution.[3]