This timely book presents a nuanced investigation into the idiosyncrasies of the supermultiplier model, examining its application to residential investment, exports and fiscal policy. It offers an accessible introduction to this growth model, hypothesising that it is one of the cornerstones of modern macroeconomics. By highlighting what this unique model adds to other heterodox systems that share common elements, such as structural growth models, this insightful book strengthens the current theoretical understanding of new macroeconomics. Utilising important case studies such as open and decarbonised economies to encapsulate key messages gained from the study of this model, it fully acknowledges that the supermultiplier is still a work in progress and may be developed further. The Supermultiplier will be hugely influential for finance and economics graduate students focusing on an alternative macroeconomics approach. It will also appeal to academics within the same fields searching for a model that permits direct application within spreadsheets.