what is polynomial distributed lag what is adstock used for why is adstock variable used what is adstock and polynomial lag which variable does adstock use what is the difference between adstock and polynomial distributed lag what is polynomial distributed lag why use adstock variables what is the difference between an adstock variable and a polynomial variable why is it important to use adstock variables in a market mix model what is the difference between adstock and polynomial lag? what is the difference between adstock and polynomial lag what is the difference between adstock and polynomial lag variable which variables in adstock variable which distribution does adstock use what is the difference between adstock and polynomial lag difference between ad stock and polynomial distributed lag what is adstock variable which is better polynomial or adstock? what is adstock variables