Where can we see informal economies take place more often in the geographic landscape and why?

Although the informal sector makes up a significant portion of the economies in developing countries, it is sometimes stigmatized as troublesome and unmanageable. However, the informal sector provides critical economic opportunities for the poor[3][4] and has been expanding rapidly since the 1960s.[5] Integrating the informal economy into the formal sector is an important policy challenge.[3]

the mediterranean sea