Long-term Vertical Contracts, Geography, and the Persistence of Brand Shares

Previous research highlights persistent differences in national brand market shares across regions, driven by geographic consumer preferences and early entry advantages (Bronnenberg et al. 2007, 2009). This study investigates the extent to which long-term vertical contracts can explain the observed geographic dispersion and persistence of national brand dominance. Using NielsenIQ data from the same product categories as Bronnenberg et al. (2007), we follow Abowd et al. (1999) to decompose the variance in brand shares into Brand × Retailer and Brand × Market effects. Results show that 50% of the variance is explained by retailer effects, compared to 20% by market effects. This suggests that some retailers use vertical contracts that favor a specific brand across all markets in which they compete, such as exclusive-dealing, slotting allowances, or category-captaincy contracts, and that these play a key role in sustaining national brand dominance documented in prior literature. By emphasizing how retailer-specific factors drive observed patterns, we complement demand-side explanations and shift attention to supply-side factors that could affect competition.