[EN] This paper analyses the factors which may explain the improvements in performance taking
place after privatisations. Using a sample of 58 Spanish privatised firms within the period
1985-2000, we find no significant mean increases in industry adjusted profitability and
efficiency following privatisation over a medium term horizon (three years), although the
results vary according to the privatised firm. More than 50% of the firms show increases in
profitability and over 45% show increases in efficiency after the first stage of the privatisation
process. When we analyse how different characteristics of the privatisation processes may
explain the observed performance changes, the results suggest that competition may play an
important role in the success of privatisation processes. Efficiency gains seem to take place in
competitive markets, not in utilities. The results also suggest some positive influence of
factors such as the entrance of foreign investors, the relinquishment of control by the State
over privatised firms and the firms’ size on the performance of privatised firms