Analysis of Sales Promotion Effects on Household Purchase Behavior

post-promotional estimates. The differences are due to rounding and due to the effect <strong>of</strong>
consecutive promotions. Household purchases <strong>of</strong> products from a specific product category
during two consecutive promotional shopping trips are both used to estimate QP. But the
first post-promotional effect and the second pre-promotional effect are missing.
In general, the effects <strong>of</strong> sales promotions on household purchase
behavior seem to be idiosyncratic, differing across the product categories. For some
categories resulting in brand switching and purchasing sooner, for other categories in brand
switching and purchasing more without purchasing sooner. Also with respect to the
interrelatedness <strong>of</strong> the reaction mechanisms differences are found across the product
categories. Accelerated purchases are sometimes corrected for by buying less during the
promotion, but also postponed subsequent purchases are encountered. But, overall, brand
switching (BS) and purchase quantity acceleration (QP, QN) seem to be the two most
prevalent effects <strong>of</strong> sales promotions across the categories.
<strong>Promotion</strong>s lead to significantly more brand switching (BS) for all 6 product
categories. These effects are as expected, all positive. The effect is the largest for c<strong>of</strong>fee
purchases. The quantity bought during the promotional period is almost twice the amount
bought during non-promotional shopping trips.
Purchase timing and purchase quantity effects are significant for some, but not for
all <strong>of</strong> the product categories. Time acceleration effects (TA) are found for candy-bar and
pasta promotions. With respect to candy-bars, it could be the case that candy-bar purchases
are mainly determined by sales promotions, being a high impulse category. With respect to
pasta, the category purchased by the smallest selection <strong>of</strong> households from our dataset,
purchases could also be very sales promotion driven as they can be seen as a substitute
category for potatoes. The positive post-promotional effects on purchase timing (TR) do
confirm our expectations. These postponing effects <strong>of</strong> the post-promotional shopping trip
even seem to be larger than that the promotional shopping trip itself was accelerated.
Significant, positive results are found for the net effect on purchase timing (TN) for two
product categories (s<strong>of</strong>t drinks and c<strong>of</strong>fee). For these two product categories, households
bought larger quantities during the promotional period (without acceleration these
promotional purchases), but postpone their subsequent purchases within these product
categories.
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