经济学人下载:农业与营养,隐性饥饿

Another paper?? confirms this. Agricultural growth reduces the proportion of underweight children, whereas non-agricultural growth does not. But when it comes to stunting (children who do not grow as tall as they should), it is the other way round: GDP growth produces the benefit; agriculture does not. As a way to cut malnutrition, farming seems nothing special.

另一篇论文证实了这一点。农业增长确实减少了体重偏轻的儿童比例，而在这一点上 非农业增长无法做到。但是在身高方面（儿童偏矮），则是另一番状况了：GDP增长可以促进儿童长高，而农业增长则无能为力。因此，谈到改善营养不良，农业并没有什么特殊效果。

Why not? Partly because many people in poor countries buy, not grow, their food—especially the higher-value, more nutritious kinds, such as meat and vegetables. So extra income is what counts. Agriculture helps, but not, it seems, by enough.

为什么呢？部分原因是由于贫穷国家的许多人都选择购买食品，而并不自己种植——尤其是那些高价值且营养价值更丰富的食物，如肉类与蔬菜类。因此，增加收入才是最重要的因素。而农业，虽然有所帮助，但还不够。

In addition, when poor people do have a bit more cash, they do not spend it all on food, as nutritionists hope (see also Economics focus). A study from Maharashtra, in western India, back in 1983, found that poor people spent two-thirds of their extra income on food; and the very poorest did not spend much more of their extra money than the least poor, even though they had just one-sixth of the income. People spent almost 40% of their additional rupees on wheat, rice or sugar: costly and (in the case of sugar) not very nutritious. So even when the poor do spend more on food, they do not buy the stuff that is most nutritious or the best value. In a forthcoming book** Abhijit Banerjee and Esther Duflo of the Massachusetts Institute of Technology conclude that “the poor seem to have many choices, and they don’t elect to spend as much as they can on food.”

此外，当穷人手里多一点钱时，他们并不会像营养学家所期望的那样，将这些多出来的钱花在食物上（参考阅读Economics focus）。一份1983年印度西部Maharashtra邦的研究报告发现，穷人将额外所得的2/3用于购买食物。而最贫穷的人与次贫穷的人相比，就算前者额外收入仅占后者的1/6，也不会花费更多来购买食物。人们额外收入中的几乎40%都用于购买小麦、大米和糖：花费颇多（尤其是糖）且营养价值不高。因此，就算穷人购买更多食物，也不等于他们能买最有营养或价值最优的食物。MIT的Abhijit Banerjee和Esther Duflo即将发行的新书如此总结道：“穷人们似乎有很多选择，但是却不愿花太多钱在食物上。”

Agriculture, then, is no magic solution. But farming could do more to improve nutrition—as is clear from countries’ widely varying records. Malawi, Bangladesh and Vietnam all increased agricultural value-added by roughly $100 a head from 1990 to 2007, and cut malnutrition by 15-20 percentage points. Egypt, Guatemala and India pushed up agricultural value-added more—yet their malnutrition rates rose.

这样看来，农业并不是万能的。但根据世界各国的各项记录来看，农业在改善营养方面还可以做的更好。从1990年到2007年，马拉维、孟加拉国和越南的人均农业增值都增加了100美元左右，营养不良比例也降低了15到20个百分点。埃及、危地马拉和印度农业增值更多——但营养不良比例反而增加了。

The success stories are instructive. In 1990 a charitable organisation called Helen Keller International started to encourage market gardens in Bangladesh, providing women (mostly) with seeds and advice. By 2003 (the year of the latest available research), four-fifths of families in the target area had gardens, against 15% in the whole country. Almost all women and children were eating green vegetables three times a week, compared with only a third beforehand. And vitamin A intake had soared. Projects like this work because they improve what people like to eat anyway.

成功的事例很有启发性。1990年，海伦??凯勒（Helen Keller）国际慈善组织开始鼓励孟加拉国开展“市场菜园”项目，为妇女（大部分为妇女）提供种子和咨询服务。到2003年（现有最新研究截止于2003年），项目区域内的4/5的家庭都拥有菜园，高于全国比例15%；且几乎所有的妇女和儿童一周能吃上三次新鲜绿色蔬菜，而之前只有三分之一。此外，维A摄入量也大量增加。类似这样的项目通常收效良好，因为它们可以改善人们的饮食。