Analysis of Sales Promotion Effects on Household Purchase Behavior

Webster (1965) found that promotion response tends to decrease when the total
number <strong>of</strong> units purchased increases, indicating a negative relationship between basket size
and promotion response.
Inman and Winer (1998) found empirical evidence that small basket customers make
a smaller proportion <strong>of</strong> unplanned purchases. This would mean that smaller basket shoppers
are less in-store promotion sensitive.
Ainslie and Rossi (1998) concluded that households with larger basket sizes are less
price sensitive, confirming the view <strong>of</strong> Bell and Lattin (1998). Large basket size shoppers tend
to be both less price sensitive and less display sensitive. Table 3.10 shows a summary <strong>of</strong>
empirical findings regarding the relationship between basket size and promotion response.
The arguments and research mentioned above led to conflicting findings. We
therefore do not propose an a priori hypothesis about the sign <strong>of</strong> the relationship.
Table 3.10: Summary <strong>of</strong> studies relating basket size with promotion response
Sign Relationship Study
+ Bell and Lattin (1998) out-<strong>of</strong>-store
Inman and Winer (1998), in-store
- Bell and Lattin (1998) in-store
Webster (1965)
Ainslie and Rossi (1998)
Hypothesis
3.3.3 Shopping Frequency
Obviously, shopping frequency and basket size are strongly negatively correlated (see also
Bell and Lattin 1998). So most <strong>of</strong> the findings that were discussed in the previous section
are also relevant for explaining the relation between shopping frequency and promotion
response. Recall that those findings were mixed and inconclusive. Additional research that
focused especially on shopping frequency also led to different and <strong>of</strong>ten opposite
conclusions. Empirical results <strong>of</strong> Inman and Winer (1998) show that consumers who shop
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