1. Regularities in purchase behavior

2. Outline • Stationary markets • The purchase of a single brand • Patterns of purchase in the entire product category

3. Stationary markets • established markets tend to be stable for medium-length analysis periods; • use of mathematical models to mimic actual purchase behavior; • these models are based on consumer or household panel data; • they can be used to provide sales norms and judge the performance of a brand;

4. The purchase of a single brand the sales equation: m = b w where: m → mean population purchase rate b → penetration w → purchase frequency

5. Patterns of purchase in the entire product category • how do penetrations and purchase frequencies vary with market share? • what is double jeopardy? • how important are sole buyers of a brand? • when consumers buy more than one brand, what determines which other brands they buy?