A case is made in this paper for investing in tropical and sub-tropical drylands, in poor or middle-income countries. These environments, their people, and their production systems have long been regarded as risky investments. This is because rural people in drylands face many challenges: •Low agricultural productivity is caused by low rainfall, high evaporation and infertile soils.

•Droughts are frequent and unpredictable, so there are large fluctuations in yields and in household incomes from year to year. •Poverty is endemic, and often made worse by distance from markets, health and education services, and safe water. •Linkages with cities or more humid areas are vitally important as most dryland peoples need to sell their labour or services, trade or graze their animals there. In poor countries generally, productivity gains in agriculture are considered by many to be a condition of broad-based economic growth, because: •about 70% of the world’s poor still live in rural areas; •agriculture provides employment for two-thirds of working Africans and 60% of Asians, and generates a third of Africa’s Gross National Income and 27% of Asia’s; •where economic growth is fastest, agricultural productivity has risen the most; •no other economic activity benefits the poor so much; •efficient agricultural production provides food at a low cost to non-agricultural consumers.

The case for drylands differs in two respects. First, the drylands face special challenges that are not generally shared in more humid regions. Second, they have fallen behind more favoured environments in agricultural, economic and social development. There is a risk that the gap will widen in future.

The case for investing in drylands rests, therefore, in (1) the size and population of drylands; (2) the achievements observed in the ‘success stories’, (3) evidence that agricultural systems are resilient; (4) that degradation is not inevitable; (5) that public investments can and do pay; (6) that policy incentives (to invest) do work; and (7) that the costs of neglect and the benefits of action are potentially huge.