零售業因存貨品項眾多，其存貨管理制度多數採用零售價法。根據國際財務報導準則及中級會計學理論可知，零售價法需計算成本率，並藉由成本率推估期末存貨及銷貨成本。然而，理論卻未探討採用零售價法之企業能否藉由進貨行為影響銷貨毛利。本研究以一家採用零售價法之大型連鎖藥妝店為個案，檢視門市進貨行為對銷貨毛利之影響。

根據模擬結果顯示，(1)當促銷檔期未跨月，若門市於檔期當月進貨高毛利商品，則在檔期當月的毛利率會上升。然而，若門市於檔期前一個月進貨，則在進貨當月的毛利率會上升，但檔期當月毛利率則下降。(2)當促銷檔期跨月時，若門市於促銷檔期的兩個月平均進貨，則促銷檔期兩個月份毛利率大致相同。(3)當促銷檔期跨月時，若是門市在促銷檔期的第一個月進貨比例高於第二個月，則促銷檔期第一個月的毛利率高於第二個月。相反地，若是門市在促銷檔期的第一個月進貨比例低於第二個月，則促銷檔期第一個月的毛利率低於第二個月。(4)無論促銷檔期是否跨月，相較於為了檔期進高毛利商品而後持續進低毛利商品之門市，為了檔期進高毛利商品而後持續進高毛利商品之門市，其毛利率較高。故根據本研究結果可知，採取零售價法之企業能藉由進貨時間點及進貨高或低毛利商品，以影響其銷貨毛利。

The retail inventory method is used by many high-volume retailers that have many different types of merchandise. According to the International Financial Reporting Standards and intermediate accounting theory, the retail inventory method is based on relationship between the cost of merchandise and its retail price. The company calculates the cost-to-retail ratio to estimate the ending inventory and cost of goods sold. However, the theory failed to explore whether gross profit is affected by the purchasing behavior of a retailer using retail inventory method. The objective of this study is to examine the impact of purchasing behavior of stores on gross profits using a chain drug store as a case study.

According to the simulation results, this study finds that (1) when a promotion is within one month and the store purchases high profit margin products in the promotion month, the gross profit rate in the promotion month increases. However, when a promotion is within one month and the store purchases high profit margin products one month before the promotion month, the gross profit rate increases in purchasing month and then decrease in the promotion month. (2) When a promotion is within two months and the store purchases products evenly within two months, the gross profit rate is the same in these two months. (3) When a promotion is within two months and the store purchases more products in the first month than in the second month, the gross profit rate is higher in the first month than that in the second month. In contrast, if the store purchases more products in the second month than in the first month, the gross profit rate in the first month lower than that in the second month. (4) Compared to the gross profit rate of stores which purchase high-margin products at the promotion period and then purchase low-margin products afterwards, the gross profit rate is higher for stores which purchase high-margin products and then continually purchase high-margin merchandise. Therefore, the results of this study show that gross profits are influenced by the timing of purchases and the gross margin of goods the store purchase.

陳瑩郿，民92年，價格促銷呈現方式對消費者商店選擇之影響—以連鎖藥妝店為例，國立交通大學管理科學研究所碩士論文。
鄭丁旺，民103年，中級會計學上，三源印刷事業有限公司。
Cohen, D. A., A. Dey, and T. Z. Lys. 2008. Real and accrual-based earnings management in the pre- and post-Sarbanes-Oxley periods. The Accounting Review 83(3): 757-787.
Cushing, B. E. and M. J. LeClere. 1992. Evidence on the determinants of inventory accounting policy choice. The Accounting Review 67(2): 355-366.
Dopuch, N. and M. Pincus. 1988. Evidence on the choice of inventory accounting methods: LIFO versus FIFO. Journal of Accounting Research 26(1): 28-59.
Eisenhardt, K. M. 1989. Building theories from case study research. Academy of Management Review 14(4): 532-550.
Morse, D. and G. Richardson. 1983. The LIFO/FIFO decision. Journal of Accounting Research 21(1): 106-127.
Niehaus, G. R. 1989. Ownership structure and inventory method choice. The Accounting Review 64(2): 269-284.
Roychowdhury, S. 2006. Earnings management through real activities manipulation. Journal of Accounting and Economics 42(3): 335-370.
Yin, R. K. 1994. Case Study Research: Design and Methods. London: Sage Publications.
Zang, A. Y. 2012. Evidence on the trade-off between real activities manipulation and accrual-based earnings management. The Accounting Review 87(2): 675-703.