Barcode scanners were introduced in the 1970s as a way to reduce labor costs in stores, particularly at checkout. This paper is the first to estimate their effect on productivity. I use store-level data from the 1972, 1977, and 1982 Census of Retail Trade, matched to data on store scanner...

We analyze the effect of Wal-Marts entry into the grocery market using a unique store-level price panel data set. We use OLS and two IV specifications to estimate the effect of Wal-Marts entry on competitors prices of 24 grocery items across several categories. Wal-Marts price advantage over...