It's my very first time in this forum.
I'm trying use 2 prices as an exogenous in a ARIMAX model. But I need to define a restriction in the first price (because doesn't make sense increase the price and the sales increase to), and leave the second price (parameter) free.
I know it's possible apply a restriction (positive or negative) on input, but i don't know if it's possible define different rules for different inputs.
it's something like that, but I thought I could use the proc hpfdiagnose. In the Input Statement is possible define REQUIRED=MAYBE(NEGATIVE), but I don't need restrict all the variable inputs, but only the price.