BOOLEAN MULTIPLICATION. Boolean multiplication differs substantially from normal multiplication Boolean multiplication is relevant because the typical social science application of Boolean algebra concerns the process of simplifying expressions known as"sums of products. "A product is a specific combination of causal conditions. With uppercase letters indicating presence and lowercase letters indicating absence, the data on collapsed military re gimes from Table 4 can be represented in"primitive"(that is, unreduced) sums-of-products form as follows F= Abc t aBc abC ABc+ AbC + abC abc occurs if any of seven combinations of three causes is obtained. In boolean algebra, therefore, addition indicates logical OR and multiplication indicates logical AND. The three causes are ANDed together in different ways to indi- cate different empirical configurations. These intersections are ORed to gether to form an unreduced, sums-of-products equation describing the dif ferent combinations of the three causes linked to regime failu ure