Finally , we need to know for whom commitment contracts are most likely to be acceptable , efficacious , effective , and cost effective . In other words , what characteristics of people make them particularly likely to take up a contract and use it to achieve behaviour change , and how might consumer detailing be used to augment contracts ' effectiveness and cost effectiveness ? We might expect that people most willing to accept commitment contracts are those who recognise their difficulties with resisting temptations and who are motivated to change this . People for whom commitment contracts have the greatest incremental efficacy may be those with particularly high levels of impulsivity . 2 However , getting such people to accept the contracts may be a particular challenge . If we can identify people in whom commitment contracts are more effective , programmes could be targeted at these groups . Such data might also suggest ways to broaden the acceptability and efficacy of commitment contracts , perhaps through interventions that help people link present behaviours to future consequences . 11