This chapter envisages that Mayotte's economy could be viewed as a significant issue for the modelization of complex systems in the systemic paradigm – a paradigm which has come into being since the second half of the 20th Century. Despite the long debate on the so-called mathematization of economics since the 19th Century, advanced knowledge in mathematics is a necessity for any postgraduate economist. Though there are several arguments for justifying the mathematization of economics, it is sufficient in the paper to group them into two categories, which are linked: the ontological argument and the linguistic one. The paper uses examples to show the fact that Mayotte's formal economy cannot be strictly separated from informal activities and that their interactions, difficult to mathematize traditionally, might be viewed as issues for the modelization of complex systems.