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The concept of opium replacement was first developed within an agricultural framework, most notably in Thailand. Agricultural engineers sought to identify crops that would generate more income than the opium poppy. In the late 1970s and early 1980's, awareness of the social and cultural roles played by opium cultivation and consumption in Northern Thailand led to a reconsideration of the parameters of the opium replacement project. Rural development projects began addressing a variety of aspects of rural life - including health, education and social issues - and the terms "opium replacement" or "opium substitution" were superseded by the concept of "integrated rural development". In the 1990s, the language again shifted to the term "Alternative Development". This term and its minor variants are still used in Latin America (where crop-replacement approaches are used as a strategy for reducing the supply of coca as well as opium). The United Nations refers to these crop replacement projects 'Sustainable Alternative Livelihoods'; in Afghanistan development agencies use the term 'Sustainable Livelihoods'.
Opium replacement around the world 
Opium has been grown in Turkey, Iran, Pakistan, Afghanistan, India, Nepal, Burma (or Myanmar), Thailand, Laos, China and Vietnam. It is believed to be grown in the Central Independent States (former Soviet states including Kazakhstan and Kyrgyzstan). Cultivation is also reported to have been successful in Mexico (reportedly imported by immigrant Chinese opium users) and to Colombia (reportedly as part of a collaboration between South-East Asian and Colombian drug traffickers). According to the United Nations Office on Drugs and Crime published in the mid-2000s, only the following countreis cultivated significant opium crops: Burma, Afghanistan and Colombia. Laos, Mexico and Pakistan produced small to intermediate amounts while Thailand and Vietnam produced negligble amounts. Of these countries, opium replacement (or alternative development) has been implemented in Thailand, Laos, Burma, Vietnam, Pakistan, Mexico and Afghanistan.
Of these countries, there have been significant opium replacement programmes in Thailand, Laos, Burma, Vietnam, Pakistan, Afghanistan, Mexico and Colombia.
The Thai Experience 
Thailand is widely considered to be the most successful example of opium replacement policies. Although peak production in Thailand was relatively low (150-200 tonnes annually), Thailand's approach to opium replacement is considered the most broad attempt to replace opium cultivation with legal agricultural crop. So far, more than 150 crops have been successfully introduced to farmers, usually from temperate climates suitable to opium growing regions including: cabbage, lettuce, kidney beans, tea, coffee, peaches, apples, herbs and decorative flowers. In general, these crops were cash crops of medium to high value. While many of these crops are not native to Thailand, they have been integrated into Thai cooking and culture. Two particularly successful opium replacement projects that are still in operation: the Royal Project (established in 1969) and the Doi Tung project (established in 1988). Both have eliminated opium cultivation from their project areas and have helped farmers improve living conditions. These model programs are studied and visited by practitioners of opium replacement from other countries.
Other national opium replacement projects
In Colombia, much of the opium cultivation takes place under the protection of armed groups opposed to the government, limiting the success of opium replacement attempts. Laos has experienced very steep declines in cultivation, but former opium farmers are often left destitute due to the dearth of licit alternative crops. A similar situation has been observed in Laos and Pakistan, and the latter is now experiencing an increase in cultivation due to overspill from Afghanistan. It is hard to comment on the process in Burma, as saying anything at all about Burma founders on the incredibly Byzantine politics of that country. The United Nations has one project in the Wa region (in the north-east), the Japanese development agency had a project for some time (that failed) and the Doi Tung project of Thailand also initiated some activities. These projects cover areas too small to have much of an effect on national production. In fact, production does seem to have been falling, but it is believed that this is simply because of a decision by warlords in Burma to concentrate on methamphetamine. At any rate, Burma is not the poster child of opium replacement. Lastly, there is Afghanistan, whose production and hectare dwarf even Burma at its peak. The opium replacement project there is a few years old now, but it is slow going, because of the scale of the cultivation, the size of the country, terrible security, destruction of infrastructure and weakness of government institutions.
Despite the success of Thailand and, to a lesser extent, Pakistan and Vietnam, many people deny that opium replacement is actually effective. The first argument is that Thailand is the only real success, but that its success is due to lots of unique and non-replicable factors. The second is that development activities simply cause production to relocate to other areas (what is often called "The Balloon Effect"). On one hand it is true that there are many farmers who don't grow drug crops as a result of agricultural and social development. On the other hand, the world's supply of illicit drugs is continually rising and prices are falling, despite the expenditure of hundreds of millions of dollars by development agencies and national governments on these kinds of projects. Despite this controversy, the programmes go on.
Organization of modern opium replacement projects 
Opium replacement projects are typically implemented by national government agencies, with the support of an international donor. Usually, the donor gives the funding and a contractor implements the project in partnership with the national agency. At the moment, the largest providers of funding are the United States Agency for International Development (USAID) and the European Union. Major contractors include the German Technical Cooperation Agency and several for-profit firms from the United States, such as Chemonics. The United Nations Office on Drugs and Crime helps to coordinate the many different efforts, and also funds a few projects. In Colombia, and Mexico, a few additional players are present, although opium replacement is a minor focus (the cultivation of coca being the major one).
Rightly or wrongly, opium replacement projects are no longer planned and executed with very long time frames, as was the case with Thailand's Royal Project, and the Doi Tung project. Nowadays, projects are more likely to take place over just two or three years.
- Mansfield, David (1991) Alternative Development: the modern thrust of supply-side policy
- Renard, Ron (2001) Opium Reduction in Thailand 1970-2000: A 30 Year Journey (Chiang Mai: Silkworm)
- United Nations Office on Drugs and Crime (2005) A global thematic review of alternative development
- United Nations Office on Drugs and Crime (2003) Global illicit drug trends 2003
- Jelmsa, Martin (2002) Alternative Development and Drug Control- A Critical Assessment