What Actually Happened to the Inventories of American Companies Between 1981 and 2000?
研究1981-2000年美国制造业上市公司库存变化，发现库存持有期中位数从96天降至81天，年均降幅约2%，其中在制品库存降幅最大（约6%/年），而产成品库存未降；高库存公司长期股票回报异常差，略低于平均库存的公司回报好，但最低库存公司回报普通。
This paper examines the inventories of publicly traded American manufacturing companies between 1981 and 2000. The median of inventory holding periods were reduced from 96 days to 81 days. The average rate of inventory reduction is about 2% per year. The greatest reduction was found for work-in-process inventory, which declined by about 6% per year. Finished-goods inventories did not decline. Firms with abnormally high inventories have abnormally poor long-term stock returns. Firms with slightly lower than average inventories have good stock returns, but firms with the lowest inventories have only ordinary returns.