The fact that the output of large economies is very volatile, instead of averaging out as the size of the economy grows, raises a question that has been at the forefront of economic research for decades. Whether it is the fat-tailed distribution of certain quantities, such as firm sizes, or network effects that are responsible for this remains unknown.

Building on the idea from Bak, Chen, Scheinkman and Woodford that economies spontaneously evolve towards an anomalously fragile marginally stable state, we present a very general framework where self-organized criticality emerges naturally. This, in turn, allows us to propose a classification of the nature of possible crises and fluctuations affecting the economy, as it is explained by the properties of eigenvectors of a matrix describing firms and their dependencies.