The world is increasingly at risk of economic fragmentation, a policy-driven reversal of global economic integration often guided by strategic considerations. This CEPR-IMF eBook brings together leading economists and policymakers to assess the economic risks of a fractured world economy and outlines avenues for future modelling, empirical and policy research. The contributions consider the impact of a fractured global economy along many dimensions, including trade, financial flows, technology diffusion and global value chains. They underscore that costs from fragmentation can be very high, even if unintended, and that emerging and low-income countries stand to lose the most. Fragmentation can also make it more difficult to provide cooperative solutions to inherently global problems, such as climate change and pandemics. Urgent action is therefore needed by politicians and policymakers to ensure that the benefits of many decades of global integration are not lost.