This publication aims to support impact evaluation in the transport sector by assessing what has been produced against what might be possible. It reviews 91 impact evaluations of transport interventions in developing countries, summarizes findings on outcomes, identifies evidence gaps, and proposes ways forward. Most of the studies reviewed find significant effects on at least one of the outcomes investigated. However, impact evaluation has given relatively little coverage to major areas of investment, such as urban and sustainable transportation, transport corridors, and efficiency enhancing measures. New methods and increasing openness of geospatial data provide scope to generate more innovative impact studies.

Impact evaluation is an empirical approach to estimating the causal effects of interventions, in terms of both magnitude and statistical significance. Expanded use of impact evaluation techniques is critical to rigorously derive knowledge from development operations and for development investments and policies to become more evidence-based and effective. To help backstop more use of impact evaluation approaches, this book introduces core concepts, methods, and considerations for planning, designing, managing, and implementing impact evaluation, supplemented by examples. The topics covered range from impact evaluation purposes to basic principles, specific methodologies, and guidance on field implementation. It has materials for a range of audiences, from those who are interested in understanding evidence on "what works" in development, to those who will contribute to expanding the evidence base as applied researchers.

This report aims to support impact evaluation in the energy sector by assessing what has been produced against what might be possible. It reviews 85 impact evaluations of energy interventions in developing countries, summarizes findings on outcomes, identifies evidence gaps, and proposes ways forward. A majority of studies has so far focused on rural electrification and improved cookstoves, while most investments are in power generation and transmission. After considering the body of evidence available, directions and approaches are proposed for future impact evaluations to best contribute new evidence regarding the sector.

Impact evaluation aims to answer whether and to what extent a development intervention has delivered its intended effects, thus enabling evidence-based policy making. The desire for more hard evidence of the effectiveness of development interventions has fueled a growing interest in rigorous impact evaluation in the international development community. This report discusses the fundamental challenge of impact evaluation, which is to credibly attribute the impact, if any, to the intervention concerned. It then discusses the merits and limitations of various impact evaluation methods. It also presents a survey of recent applications of impact evaluation, focusing on the typical evaluation problems looked at, methods used, and key findings. The report includes six case studies and outlines practical steps in implementing an impact evaluation.

Ex-post evaluation is important to improving the delivery of transport policy objectives. It can be used for multiple purposes at the core of which is the improvement of ex-ante assessment. A small number of jurisdictions employ ex-post evaluation systematically and leading experience is ...

The second edition of the Impact Evaluation in Practice handbook is a comprehensive and accessible introduction to impact evaluation for policy makers and development practitioners. First published in 2011, it has been used widely across the development and academic communities. The book incorporates real-world examples to present practical guidelines for designing and implementing impact evaluations. Readers will gain an understanding of impact evaluations and the best ways to use them to design evidence-based policies and programs. The updated version covers the newest techniques for evaluating programs and includes state-of-the-art implementation advice, as well as an expanded set of examples and case studies that draw on recent development challenges. It also includes new material on research ethics and partnerships to conduct impact evaluation. The handbook is divided into four sections: Part One discusses what to evaluate and why; Part Two presents the main impact evaluation methods; Part Three addresses how to manage impact evaluations; Part Four reviews impact evaluation sampling and data collection. Case studies illustrate different applications of impact evaluations. The book links to complementary instructional material available online, including an applied case as well as questions and answers. The updated second edition will be a valuable resource for the international development community, universities, and policy makers looking to build better evidence around what works in development.

This White Paper sets out a strategic policy framework for the development of airport capacity in the UK over the next 30 years. Chapters focus on the following: the strategic framework; the environmental impacts; the air transport sector. It also looks at individual regions and the impact for them, including: Scotland, Wales and Northern Ireland, also the North of England, the Midlands, the South West and finally the South East. The framework itself can be used by public bodies, air operators and airlines for future planning applications. It also sets out the Government and devolved administrations' conclusions on the case for future airport expansion, taking into account the large consultation exercise of over half million respondents. This paper provides reasons why airport capacity should be expanded, but recommends a balanced approach to the issue. Among the reasons are: the economic importance of air travel for the country’s economy and the increased desire amongst the population for foreign travel, which should be balanced against minimizing, where possible the environmental effects to an area where airports are situated. These are some of the main cases for future development following a full environmental assessment: for Scotland: an additional runway at Edinburgh Airport; substantial terminal development at Glasgow Airport. For Wales: further terminal development needed at Cardiff airport. For Northern Ireland: development of increased capacity at Belfast. For the North of England: additional terminal capacity provided at Manchester Airport and development of increased capacity at Liverpool John Lennon Airport. For the Midlands: additional runway for Birmingham. For South West England: expansion of Bristol Airport. For South East England: a new runway at Stansted; further development of Heathrow supported, including a further runway and additional terminal capacity. Some options though are not to be followed through, including: two new runways at Gatwick, a development of a second runway at Luton, and a new airport at Cliffe, a new airport of central Scotland, and a new airport at Rugby.