Stomach staples填饱肚子的主食

Economics focus经济焦点
Stomach staples填饱肚子的主食

 

People's spending choices are a good way to assess levels of hunger人们的食物花销能有效评估饥饿程度
Mar 24th 2011 | from the print edition

 

 

 

FOR most people in rich countries hunger is a temporary inconvenience, easily solved by popping out to the shops or raiding the fridge. But chronic hunger is part of everyday life for many people in poorer places. Halving the proportion of people in developing countries who do not get enough to eat is one of the United Nations' Millennium Development Goals.
对发达国家的群众来说，饥饿是一小会儿的不适，跑个商店或扫下冰箱就很容易解决。在贫困地区有很多人却天天过着挨饿的日子。联合国"千年发展目标"之一是发展中国家的挨饿人口比例减半。

 

Reducing hunger is a complicated task. There is no global shortage of food. Less poverty does not always mean better-nourished people. In India, for example, real incomes rose and the price of food fell between 1980 and 2005. Yet evidence suggests that Indians, even those who were originally eating less than recommended, reduced their calorie consumption in that time. Such findings have long puzzled economists.
全球食物不紧缺，不过减少饥饿却是个复杂的任务。不太穷又不是总和好营养挂钩。例如印度1980至2005年，人们实际收入涨了食物价格也降了，但是数据表明，即使是那些原来就吃不好的印度人，在那段时间还减少了热量消耗，这种事让经济学家头疼了很久。

 

A recent paper* by two economists, Robert Jensen of the University of California, Los Angeles, and Nolan Miller of the University of Illinois, Urbana-Champaign, suggests that part of the problem may lie in the way governments and international agencies count the hungry. This typically involves fixing a calorie threshold―2,100 calories per day is a common benchmark―and trying to count how many people report eating food that gives them fewer calories than this number. Since calorific needs differ from person to person, a universal number is clearly only a guide. What's more, concentrating on calories ignores the important role of micronutrients such as minerals and vitamins (see article). But the economists argue that this approach to measuring hunger also does not accord with how people themselves think about it. They propose a new way to use people's eating choices to tell whether they are hungry.
洛杉矶加利福尼亚大学的经济学家Robert Jensen和伊利诺伊大学厄本那香槟分校的经济学家Nolan Miller发表的论文表示，部分也许因为政府和国际机构统计饥饿数据，通常会定下门槛――每天2100卡路里是个统一标准，并试着统计有多少人摄取的卡路里低于这个标准。既然人们的卡路里需求量不一样，一个统一标准显然只能做参考。此外，注重卡路里而忽视了矿物质和维生素等微量元素的重要。但经济学家却表示这主要为了评估饥饿程度，当然不能和人们自主想的那样，不过他们提出了一个新方案：用人们的食物花销来评估饥饿程度。

 

Hunger is a physically unpleasant experience: it is accompanied by headaches, pain, dizziness, loss of energy and an inability to concentrate. For a hungry person, therefore, the extra utility from more calories is extremely high. The economists argue that the pain caused by hunger will prompt insufficiently nourished people to spend a larger share of their food budget on staples like rice and millet, which are cheap sources of calories. But once people are no longer hungry, they do not need to spend their incremental cash on the cheapest source of calories but can base their choices on things like variety and taste. This means that the share of calories that comes from staples falls progressively once a person is no longer famished; and that an unusually high share of calories coming from staples indicates that a person is hungry.
饥饿导致身体不舒服，伴随着头痛、难受、头晕、没劲儿和注意力不集中。因此饥饿的人急需更多的卡路里。经济学家提出，饥饿引起的痛苦将会推动营养不够的人花更多的钱去买大米或小米等主食，都是便宜的卡路里来源。不过一旦人们摆脱了饥饿，他们不再多花钱买这些，而是注重多样和味道。这表示人们不再饥饿，主食卡路里分量会大大下降；若主食的卡路里分量异常之高则表明人们处于饥饿状态。

 

How high is unusually high? By looking at the prices of various foods, it is possible to work out what share of a person's calories would come from staples such as rice and wheat if he were trying to fulfil his dietary needs as cheaply as possible. This theoretical "staple calorie share" (SCS) can then be compared with the make-up of a person's actual diet. Someone who is consuming a significantly higher share of calories from staple foods than predicted is likely to be hungry.
多高才算饥饿？得看食物价格，如果人们试着尽可能便宜的满足饮食需要。由价格可能算出他们大米或小麦等主食卡路里的摄取量，理论上的"主食卡路里分量"（SCS）因此可同人们实际饮食构成对比，若有人消耗比预测还高很多的主食卡路里，他很可能处于饥饿之中。

 

This approach would be far too cumbersome if each person's SCS varied greatly but things turn out to be considerably simpler. Using accepted dietary guidelines for people of various sizes and ages, and data on food prices for parts of China, the authors find that the share of calories that ought to come from staples varies much less than overall calorific needs. Wide variations in people's age, sex, physical condition and lifestyle (more exercise, say) mean that some people need as little as 2,112 calories per day, while others may require as many as 3,202 calories. But the authors find that most calculated SCSs remain in a narrow band between 80% and 85% of overall calories. What this suggests is that someone getting less than 80% of his or her calories from a staple is past the point where conquering hunger is the primary motivation driving food purchases.
如果每个人的"主食卡路里分量"有很大的不同，这个办法就会很麻烦，不过也事情变得相对更简单，在中国部分地区，对体重和年龄不同的人使用统一的饮食标准和食物价格，作者发现，应该来自主食的卡路里分量比总体所需卡路里要少得多。人们的年龄、性别、身体状况和生活方式（比如多运动）有很大的差距，一些人每天只需要2112卡路里，而其他人可能需要多达3202的卡路里。精算的"主食卡路里分量"停在总卡路里的80%到85%这一小段。摄取少于所需主食卡路里80%的人证明战胜饥饿是购买食物的原动力。

 

The economists use this threshold to measure the extent of undernourishment in nine Chinese provinces, where 16,000 individuals in 3,800 households were surveyed several times between 1991 and 2000. The people who were surveyed had to report everything they had eaten or drunk the previous day. The survey data conformed with the basic idea of substitution: the poorest households ate little other than staples. As income rose above a certain level, however, the SCSs dropped. People seemed to move out of the danger zone once their monthly income exceeded 225 yuan ($27 in 2000).
在中国的九个省，经济学家使用2100卡路里标准评估饥饿程度，1991年至2000年间，3800户中16000名居民接受了几次调查，接受调查的人们需要汇报前天食用的食物和饮料，调查数据和这个办法基本相符，：最穷的家庭以主食为主。随着收入高过一定标准，"主食卡路里分量"则会下降，一旦人们每月收入超过225元（2000年为27美元），他们似乎能摆脱饥饿的困扰。

 

Pulse taking评估
The data show how many people get less than four-fifths of their calories from rice, the main staple in most of the areas studied. Here, the results contradict what the Chinese government's standard 2,100-calorie-per-day threshold would find. Around 67% of households in the sample were undernourished by the standard measure in 2000, but only 32% got more than 80% of their calories from staples. This is a big difference. Using data on people's choice of what to eat leads to an estimate of hunger that is about half as large as the estimate using the standard method.
数据显示，在大部分的调查地点，有多少人从大米这种主食摄取的卡路里少于五分之四。我们可以看出，结果同中国政府每天2100的卡路里标准相悖。2000年在调查地大约67%的家庭达不到这个标准，只有32%家庭摄取超过80%的卡路里。以人们的食物花销来评估饥饿程度同标准方法差了一半，可真是个大差距。

 

The two measures also give opposing results about long-term trends in hunger. The average household in the sample got richer between 1991 and 2000, but the fraction that consumed less than the mandated daily number of 2,100 calories actually rose, from 53% to 67%. The share of calories coming from staples points in a different direction, however: by this measure, the number of hungry households dropped from 49% to 32% over this period. More recent evidence suggests something similar. A 2008 study found that giving poor Chinese households subsidies on staple cereals failed to lead people to consume more rice or wheat. Instead, they ate more shrimp and meat. Not necessarily the cheapest source of calories, but considerably tastier.
两种办法也在饥饿问题的长期趋势上产生了相反的结果。1991至2000年间调查地的一般家庭都变富了，每天摄取少于2100卡路里标准的小部分也从53%升到67%。主食卡路里分量产生了分歧，然而，这段时间第二种办法测得饥饿家庭的数量从49%降到32%，最近更多的数据也得出了和第二办法相似的结论。2008年调查发现，给中国贫穷家庭谷类主食津贴不能让他们多买大米或小麦，相反他们买了不少虾和肉，这些不一定是最便宜的热量来源，但却是相当美味的