During evaluation one should consider what would have happened in the absence of assistance. To produce an assessment of this counter-factual scenario involves considering the twin concepts of deadweight and displacement. An evaluative framework is developed for measuring the impact of grant assistance to individual firms. Logit regression analysis is used to estimate predictive models for deadweight and displacement. The data used were gathered during face-to-face interviews with the managing directors of firms that received grants from Shannon Development in the Shannon region of Ireland (self-assessment approach). The objective of the study was to establish whether certain characteristics of grant-assisted firms could predict probable deadweight and displacement effects. In the case of deadweight, factors found to influence the level of deadweight included grant type, size of firm, whether a firm's appraisal of investments included grants received, and whether a firm was a first-time or repeat grant recipient. Regarding displacement, it was found that size of firm and type of ownership had an impact. While the evaluative framework has been 'tested' in an Irish regional context, the logic of the approach is clear and has a much wider international applicability in the evaluation of industrial policy interventions.