 We compare the evolution (from January to May 2020 ) of the daily mobilityflows in Italy, measured by means of nation-wide mobile phone data, and the evolution of transmissibility, measured by the net reproduction number, i.e., the mean number of secondary infections generated by one primary infector in the presence of control interventions and human behavioural adaptations. We find a striking relationship between the negative variation of mobility flows and the net reproduction number , in all Italian regions, between March 11th and March 18th, when the country entered the lockdown.
<coherence>  We compare the evolution (from January to May 2020 ) of the daily mobilityflows in Italy, measured by means of nation-wide mobile phone data, and the evolution of transmissibility, measured by the net reproduction number, i.e., the mean number of secondary infections generated by one primary infector in the presence of control interventions and human behavioural adaptations. We find a striking relationship between the negative variation of mobility flows and the net reproduction number , in all Italian regions, between March 11th and March 18th, when the country entered the lockdown.
 We compare the evolution (from January to May 2020 , we find a striking relationship between the negative variation of mobility flows and the net reproduction number , in all Italian regions, between March 11th and March 18th, when the country entered the lockdown.