A novel perspective on scientific fraud—how undisclosed “tweaks” to research designs and model specifications fuel the credibility crisis in science. In The Credibility Crisis in Science , leading social scientists Thomas Plümper and Eric Neumayer argue that the most impactful fraud is crucially under-recognized. While data fabrication and manipulation are widely recognized as fraudulent, “tweaks”—the intentional selection of research designs and model specifications based on the results they give—are not. As a consequence, the credibility crisis in science is even more severe than both scientists and the public believe. The authors show how easily observational data analyses, experimental designs, and causal models are tweaked in ways that are extremely difficult, often impossible, to detect. They also argue that conventional strategies to deter, prevent, and detect fraud will not work for tweaks. They put forth two potential solutions: first, a classification system that categorizes data based on its susceptibility to manipulation and the probability of such manipulation being identified; and second, the proposal that journal editors and reviewers, rather than authors, select robustness tests. ENDORSEMENTS “Data fabrication and manipulation damage scientific credibility. Plümper and Neumayer argue that ‘tweaking’ is an even more prevalent and problematic form of scientific fraud. A must-read for anyone trying to counter declining trust in science.” —Matt Golder, Professor of Political Science, Pennsylvania State University “This is a tremendously important and well-written book. It tackles the problem of scientific fraud with a depth and clarity that I found both novel and persuasive. The authors have convinced me that the ‘gray zone’ of scientific misconduct—what they call tweaking—deserves far more attention than I gave it in my own work. This is a book that deserves to be widely read.” —Lee McIntyre, author of On Disinformation and How to Talk to a Science Denier “Tweaking and fraud provide background conditions under which routine junk science can thrive. This new book provides a thoughtful tour of the problem and potential solutions.” —Andrew Gelman, Higgins Professor of Statistics, Columbia University; author of Regression and Other Stories “This book cuts through the fog of questionable research practices to show why science too often fails to deliver on its promise, and what can be done about it. A sharp, timely, and essential read.” —Abel Brodeur, Professor, University of Ottawa; Founder and Chair, Institute for Replication Thomas Plümper is Professor of Quantitative Social Research at the Vienna University of Economics and Business and Head of the Department of Socioeconomics. He is author of numerous articles and coauthor, with Eric Neumayer, of Robustness Tests for Quantitative Research . Eric Neumayer is Professor of Environment and Development at the London School of Economics and Political Science (LSE) and a recipient of the Philip Leverhulme Prize in Geography. He is LSE’s Deputy President and Vice Chancellor.