Pre-print, Working paper: Using an exhaustive database with labour, accounting and financial market information on French firms (1994-2000), the authors analyse the causes and the consequences of a workforce reduction in 1996 – the year chosen as reference – on firms' performance in a long term perspective. One important contribution to the topic consists in comparing the estimates of publicly-listed and non-listed companies. As far as we know, the comparative method had not be used before. A logistic model shows that in both groups, headcount reduction occurs in less-productive and financially distressed firms, resorting to downsizing as a defensive response to an adverse economic shock. However, the former anticipates better than the latter the decision to eliminate jobs. An econometric model that captures the initial characteristics of the firms, suggests the major performance indicators are significantly improved only for non-listed companies. Yet, there is no net gain on the full period studied.