• Hindsight experience is not adequately shared because it is restricted to limited-circulation consultancy reports or academic journals which poor countries cannot afford to access; also, post-development appraisals are seldom satisfactory because there is scarce funding, or those involved do not want to highlight ‘shortcomings’.
• The art of precautionary planning has evolved quite recently and is still being adapted to real-world conditions; consequently, it is easily sidestepped, or is applied too late to select the best development option, or it is misused or neglected, or just lacks the power to identify impacts well enough.
• Funding may be allocated to developments which satisfy powerful special interest groups or bolster national prestige, rather than produce maximum utility with minimum environmental and social impacts.
• Expatriate and indigenous ‘middle-class’ experts and decision makers are reluctant to ‘rough it’ in the countryside, leading to slow responses to problems and patchy oversight.
• Civil unrest and lack of investment conspire to prevent collection and maintenance of adequate baseline data, or servicing of infrastructure and law and order.