This paper presents a new model of firms' decisions on training in a context of potential worker mobility. Such worker mobility can be influenced by employers coordination, namely through the operation of no-poach agreements and employers' associations (EAs). We then present supporting evidence from rich matched panel data, including firms' EA affiliation and workers' training levels. We find that workers' mobility between firms in the same EA is considerably lower than mobility between equivalent firms not in the same EA. We also find that training provision by EA firms is considerably higher.