A policy tool for the screening of a given policy proposal, in order to detect and assess its differential impact or effects on women and men, so that these imbalances can be redressed before the proposal is endorsed. An analysis from a gender perspective helps to indicate whether the needs of women and men are equally taken into account and served by a given proposal. It enables policymakers to develop policies with an understanding of the socioeconomic reality of women and men and allows for the development of policies that take (gender) differences into account. Gender impact assessment can be applied to legislation, policy plans, policy programmes, budgets, concrete actions, bills and reports or calls for research. Gender impact assessment methods do not have to be applied exclusively to policy in the making; they can also be applied to existing policies. They can be used in the administration as well as by external actors; in both cases, they require a considerable amount of knowledge of gender issues. The advantage of these tools lies in the fact that they draw a very accurate picture of the effects of a given policy.