The aim of this paper is twofold. First, it will be argued that the flexibility in labour contract duration can be ineffective in increasing productivity, profits and employment when workers test a high state of uncertainty. Second, it will be shown that these effects can be reduced when firms put into effect a system of social responsibility. What emerges is that while flexibility produces unstable collaborative behavioural codes between employers and employees that damage both, the firms’ social responsibility contributes to spread a spirit of shared values and personal gratifications amongst workers that reduce this instability and generate positive economic performances.