맥주 주세가 소매점 번들링에 미치는 영향: 종가세에서 종량세로의 전환

Using a bundling model, this study analyzes how retail bundling strategies changed following the 2020 reform of Korea's beer taxation system, which shifted from an ad valorem tax to a specific tax. Under the ad valorem system, structural differences in the tax base between imported and domestic beer resulted in higher tax burdens on domestic beer, leading to widespread retail strategies that bundled only imported beer. This study demonstrates that such imported-beer-focused bundling was a response to the discriminatory tax structure under the ad valorem regime. The analysis assumes a market structure consisting of two domestic brewers and two import distributors supplying a monopolistic retailer. Using marginal costs that include selling and administrative expenses, the model simulates the retailer's optimal bundling strategy. There exists a range of costs under which bundling only imported beer is optimal for the retailer under the ad valorem tax. Within this range, a shift to a specific tax leads to a different optimal strategy, where bundling both domestic and imported beer becomes profit-maximizing. While a sufficiently low specific tax rate may enhance consumer welfare, retailer profit, and tax revenue, the Pigovian nature of the tax suggests that such a rate reduction may be difficult to justify from a welfare perspective.