This article examines the dynamics of the informal sector in Madagascar during the 1995–2004 period, which was characterized by sustained growth that ended due to a major political crisis. As conventionally assumed by simple dualistic models, the informal sector indeed fulfils a labor-absorbing function in times of crisis. However, informal business creation was also a major trend both during macroeconomic growth and during crisis and recovery. Growth in the informal sector was mostly extensive, with little job creation or capital accumulation. Although such a situation would be consistent with the existence of poverty traps, estimated marginal returns to capital are decreasing, which tends to reject this hypothesis.