Ferguson's latest book is certainly a good read, and presents a clear argument about Africa's engagement with the global system. While much of the book draws heavily from work that Ferguson has already published (for example the chapter on Chrysalis in Zambia), he has managed to pull together the strands of his previous research to generate a new set of arguments. Ferguson maintains that Africa is unique because the informal/illicit economy is deemed to be larger than the formal economy; Africa is a continent where much is unknown and unknowable. He uses the idea of ‘shadows’ to explain the complex processes at work when we try to understand how ‘Africa’ engages with the international system: this involves a kind of doubling – in the case of the economy, the shadow and formal economies run in parallel with one another. Ferguson argues that the formal economy can be understood as an implicitly Western model, and the shadow is the dark African version. Ferguson extends his argument further to suggest that the shadow is not a copy, instead it is an attached twin: it is not a negative space or a space of absence, but rather it is a likeness, which is inseparable for the formal version (p. 17). As such, his work builds on and challenges previous studies of the informal economy and ‘shadow states’ by academics such as Reno and Nordstrom.

One of Ferguson's core claims is that ‘Africa is and is not global’ (p.29), so that understanding Africa in the international system sheds new light on what we mean by globalisation; most notably, he argues that capital hops and skips across the continent, so that there are there are two types of Africa emerging, what French colonialists called Afrique utile and Afrique inutile: that is usable/useful Africa versus unusable/useless Africa (p. 39). In terms of debates about the nature of sovereign power in sub-Saharan Africa, Ferguson's argument is clear: that sovereignty in Africa is not about control over territories, it is instead the ability to provide contractual legal authority to extractive foreign firms. Political instability, and even civil war, do not interfere with such forms of sovereignty, partly due to the patchwork of private security offered to enclaves (p. 207).

This is an extremely useful book for anyone interested in understanding the complexities of Africa's role in a neoliberal world order. Its arguments can be used to provoke further discussion on how parts of Africa that are drawn into the global economy are distinct and separate from the areas ‘left behind’ by the neoliberal world order. In many cases, marginalisation, exclusion and poverty exist hand in hand with inclusion and wealth, in a way that fits well with the notion of the shadow as the attached twin.