Using panel data on the publicly traded firms in the US manufacturing sector in the recent past, I find that most of the change in employment at the firm level in any given year is permanent, that year-to-year growth rates are largely uncorrelated over time or with prior characteristics of the firm, and that there is almost no measurement error. Gibrat's Law is weakly rejected for the smaller firms in my sample and accepted for the larger firms. This finding remains when I control for the effect of selection (attrition) on estimates obtained from this sample.