Ojima, MayumiShino, JunnosukeUeda, Kozo2025-03-272025-03-27https://hdl.handle.net/1885/733743498This paper considers the macroeconomic effects of retailers' market concentration and buyer-size discounts on inflation dynamics. During Japan's "?lost decades,"? large retailers enhanced their market power, leading to increased exploitation of buyer-size discounts in procuring goods. We incorporate this effect into an otherwise standard New- Keynesian model. Calibrating to the Japanese economy during the lost decades, we find that despite a reduction in procurement cost, strengthened buyer-size discounts did not cause deflation||rather, they caused inflation of 0.1% annually. This arose from an increase in the real wage due to the expansion of production.en-AUAuthor(s) retain copyright2014-01