Klenow and Kryvtsov (2008) Prices are collected by 400 employees, who visit 20,000 retail outlets a month, mainly in 45 large urban areas Findings: price changes are freuquent, price cahnges are large in abs alue, many price changes are small, price durations are variable, hazard rate are flat, size of price change is unrelated to time, intensive margin dominate the variance of inflation (intensive margin: average size of price change)