1. A computer implemented method of determining a pantry loading effect on sales of a product, comprising: determining a plurality of decremental effect factors, each corresponding to a respective one of a plurality of weeks, wherein at least some of the decremental effect factors are indicative of a downward trend in sales of a product that was under a promotion condition during a first one of the plurality of weeks; determining a plurality of decremental effect terms, each decremental effect term equal to the product of a corresponding coefficient multiplied by a corresponding one of the decremental effect factors; determining a pantry loading effect term based on the plurality of decremental effect terms; determining a pantry loading incremental sub-volume based on the pantry loading effect term; and generating a report including the pantry loading incremental sub-volume.