What is the rationale behind the choice of the largest difference and the subsequent choice of the smallest cost in the corresponding row or column? The largest difference at any stage of VAM is a measure of the “regret” we would have for not using the smallest cost possible in the row or column of this difference. Referring to the tableau above, if we do not take advantage of the 2 in the third column, then, because of the larger difference, we will eventually have to use a much larger cost to fulfill the demand of M3. Hence we ship as many tons of widgits as we can via the cost of 2 in the hope of avoiding the much larger costs in the same column.