Supplementing coca crops with grain cultivation will be good for Bolivians and may help to reduce net coca cultivation in Bolivia in the short run, but it is unlikely to curb global drug production in the long run. The cost of coca leaf or coca paste for narcotraffickers is but a tiny fraction of the final street value of cocaine in consuming countries.
Ultimately, traffickers and middlemen can afford to pay farmers much more for the raw ingredient without significantly cutting into their net profits. Thus, traffickers can afford to outbid the market prices for rice and corn. One cannot make a direct comparison between the economics of legal grain production with the incredible risk premiums available in the prohibition drug economy. The folly of our lawmakers (as evidenced in Plan Colombia) has been to urge coca farmers to ‘simply’ grow legal crops, but the regions in which they live are often remote and undeveloped.
A kilo of paste is easy to transport and sell. It’s much harder to grow hundreds of kilos of fruitsand vegetables that must be transported on vehicles farmers do not have, over roads that literally don’t exist, to sell in domestic and international markets to which they don’t have access, and to compete against cheaper imports from international agribusiness (often subsidized by US taxpayers) against which they don’t stand a chance.