Regulatory Impact Assessments (RIAs) are designed to enable policy makers to assess the need for, and impact of, new regulations. In 2005 Government departments produced around 200 'Final' RIAs. They have been used to assess the likely economic, social and environmental impacts of the proposed regulation, and the range of options for implementing it. They have grown in scope in recent years as additional assessment criteria, such as sustainable development, have been added. Departments have primary responsibility for undertaking RIAs, and the Better Regulation Executive (BRE), which forms part of the Cabinet Office, has primary responsibility for taking forward the Government's Better Regulation agenda. The National Audit Office focused its examination on four departments - Culture, Media and Sport (DCMS); Trade and Industry; Home Office; and Transport (DfT). RIAs are often not used in the right way. The purpose of RIAs is not always understood; there is a lack of clarity in the presentation of the analysis; and persistent weaknesses in the assessments. RIAs are only occasionally used to challenge the need for regulation and influence policy decisions. If used well, RIAs can offer an effective tool for assessing different options and identifying regulatory solutions that do not impose unnecessary costs on those being regulated. There are three ways the BRE should bolster RIAs. Firstly, it should re-emphasise that economics should lie at the heart of RIAs, considering market failure, counterfactuals, competition, and how consumers and organisations behave. Secondly, RIAs need to be supplemented by a broader toolkit that policy makers can use earlier in the life of a policy. Thirdly, the BRE could re-emphasise the importance of the RIA process in challenging the introduction of new regulations.