This paper analyses how the under-investment in firm financed training caused by hold up can justify the introduction of firing taxes in a laissez - faire economy with search frictions and risk neutral agents. In particular, we show two main results. First, the introduction of a firing tax for newly hired workers combined with hiring subsidies, always acts as a Pareto improving policy. Second, with no hiring subsidies, the introduction of a firing tax for the newly hired always increase the welfare of employed while its impact on the welfare of unemployed depends on the returns to training. Hence, policy implications are derived.