In Mali, as in most West African countries, the informal sector accounts for nearly 55% of GDP, with strong sectoral differences. Its share of value added thus ranges from nearly 98% in the primary sector to 22% in the secondary sector and 66% in the tertiary sector. While the structure of the Malian economy does not differ significantly from that of most other African countries, certain characteristics of underdevelopment appear far more pronounced. Mali is landlocked, classified among the least developed countries, with a very high incidence of poverty. Moreover, the instability and conflict that have prevailed since 2012, driven by the rise of Islamist religious radicalism, have further worsened the situation. This book forms part of a long series of studies conducted in various countries, involving a wide range of researchers under the direction of Ahmadou Aly Mbaye. These studies, which focus on the informal sector, employ a similar methodology and have covered more than a dozen African cities. The most recent research, carried out in countries affected by conflict (Mali, Niger), has significantly improved our understanding of the informal sector by examining how it manifests itself in contexts of fragility. While institutional factors, such as governance, play a significant role in triggering and exacerbating conflicts, economic vulnerability (unemployment and underemployment) acts as a powerful amplifying factor. In addition, insecurity resulting from the crisis tends to further shrink the formal sector and thereby contribute to the expansion of informality. The issues discussed in this volume are fully consistent with those examined in other national and regional contexts. As such, it offers interesting comparative perspectives, both with regard to the characteristics and operating modes of actors in the formal and informal sectors, and with respect to the public policies implemented. New themes are also addressed in this book, which are directly or indirectly linked to Mali’s status as a country affected by conflict.