This book focuses on recent advances made in the field of non-linear dynamic modelling in economics. Mathematically, linearity is a very special kind of relation between variables chosen to the purpose of simplification. Even in physics linear modelling of dynamical systems was a first choice for quite some time, due to convenience in analysis, as exemplified by the acceleration law, the harmonic oscillator, the wave equation, and the like. The methods of analysis were simply developed to the ease of dealing with such systems. These methods are found under the heading of infinitesimal calculus - at early stages dynamical processes were formulated as differential equations in continuous time.