FOOD SECURITY RESEARCH PROJECT COMMERCIAL DYNAMICS IN ZAMBIA’S CASSAVA VALUE CHAIN By Steven Haggblade and Misheck Nyembe WORKING PAPER No. 32 FOOD SECURITY RESEARCH PROJECT LUSAKA, ZAMBIA AUGUST 2008 (Downloadable at: http://www.aec.msu.edu/agecon/fs2/zambia/index.htm)