Populating new variable using vlookup with multiple criteria in another variable
问题 1) A new variable should be created for each unique observation listed in variable sku , which contains repeated values. 2) These newly created variables should be assigned the value of own product's price at the store/week level, as long as observations' sku value is in the same subcategory ( subc ) as the variable itself. For example, in eta2,3, observations in line 3, 4, and 5 have the same value because they all belong to the same subcategory as sku #3. [ eta2,3 indicates sku 3, subc 2.]