Lewis himself recognized that
the distinction between traditional and modern activities did not coincide with rural and urban,
as shown by the quote above. Much attention now focuses on raising productivity of the urban
informal sector (e.g. Fox and Sohnesen 2012) but agriculture may be more promising. The
products of the urban informal sector are predominantly non-tradable services or artisanal
manufacturing, with minimal exporting. Exports of traditional and non-traditional agricultural
cash crops, however, are a viable African alternative to manufacturing for labour-intensive
export-led growth (Golub et al. 2008; Brenton et al. 2009). This issue is discussed in more detail
in the next section.