Many books have been written about Doyne Farmer and his work, but this is the first in his own words. It presents a manifesto for how to do economics better. A tale of science and ideas, Farmer fuses his profound knowledge and expertise with stories from his life to explain how we can bring a scientific revolution to bear on the economic conundrums facing society. Using big data and ever more powerful computers, we are now able for the first time to apply complex systems science to economic activity, building realistic models of the global economy. The resulting simulations and the emergent behavior we observe form the cornerstone of the science of complexity economics, allowing us to test ideas and make significantly better economic predictions – to better address the hard problems facing the world.