India's middle class, defined as those able to spend between $2 to $20 a day in 2005 purchasing power parity dollars, has expanded to about 420 million, according to an Asian Development Bank report on Asia's middle class out Thursday.

But compared with China, India has more of its middle class precariously perched just above the poor, a spot from where it is very easy to tumble back into poverty.

These are the people who live on between $2 and $4 a day. That's about 20 to 40 rupees a day in nominal terms (using an exchange rate of 15.66 rupees to one purchasing power parity dollar) or between 4,700 rupees to 9,400 rupees a month for a family of five.

'Making the middle class stay middle class is very important. In India the majority of the people are still in the lower middle class,' the Asian Development Bank's chief economist, Jong-Wha Lee, said as the findings of the report that looked at Indian data from fiscal years 1994 and 2005 were released in Delhi. 'These groups are very vulnerable. If they lose their job or if there are major shocks, they will go back to poverty.'

The people in the vulnerable lower middle class category number about 244 million, almost 60% of the middle class. India also has about 26 million affluent people, those who can spend more than $20 a day.

Figuring out how big the middle class is, is a tricky business. The ADB report notes that by using spending between $2 and $13 a day as the gauge, the World Bank's Martin Ravallion puts India's middle class at 264 million. Meanwhile, if you restrict the definition of middle class to the number of people who can spend $10 a day and yet are not in the top 5% of the population by incomedistribution, economist Nancy Birdsall suggests India would have no middle class at all.

Perhaps one of the most striking charts in the Asian Development Bank report is one that shows the distribution of people in India in absolute numbers by consumption level. What you see is a very bottom-heavy pyramid with a massive base that quickly narrows. Above that massive base, most spending groups seem to have just about doubled in size since the 1990s. The affluent appear to have more than doubled. But the size of the base of poor people doesn't appear to have changed.

China's 'pyramid,' meanwhile is sort of diamond shaped, with fewer than a 100 million people living on less than $2 a day. More of its population falls in the 'mid middle class' category that can spend $5 to $10 a day than into any other category. This group, in absolute numbers, appears to have quadrupled between 1995 and 2007.

While the apparently static block of poor people accounts for a shrinking share of Indians (because of growth in the population), it's hard not to be discouraged by the fact that even as millions of people have moved into the lower middle class, the absolute number of poor people in India has changed very little.

The report put the number of poor people in India--those living on less than $2 a day--at about 651 million people.

'Population growth has a big impact in India,' said Lee. 'This poor group has much higher fertility and larger household size and that is why you need to constantly focus on moving them to the middle class.'

Tripti Lahiri

• indian [´indiən] a.印度的 n.印度人 (初中英语单词)
• meanwhile [´mi:n´wail] n.&ad.其间；同时 (初中英语单词)
• income [´inkʌm] n.收入，所得 (初中英语单词)
• distribution [,distri´bju:ʃən] n.分配；分布(状态) (初中英语单词)
• striking [´straikiŋ] a.显著的，明显的 (初中英语单词)
• absolute [´æbsəlu:t] a.绝对的 n.绝对 (初中英语单词)
• constantly [´kɔnstəntli] ad.经常地；不断地 (初中英语单词)
• consumption [kən´sʌmpʃən] n.消耗；结核病 (高中英语单词)
• massive [´mæsiv] a.厚实的；魁伟的 (高中英语单词)
• apparently [ə´pærəntli] ad.显然，表面上地 (高中英语单词)
• economist [i´kɔnəmist] n.经济学家；节俭的人 (英语四级单词)
• restrict [ri´strikt] vt.限制；限定；约束 (英语四级单词)
• definition [,defi´niʃən] n.限定；定义；明确 (英语四级单词)
• fiscal [´fiskəl] a.财政的 (英语六级单词)
• category [´kætigəri] n.种类；部属；范畴 (英语六级单词)
• impact [´impækt] n.影响，作用；冲击 (英语六级单词)
• fertility [fə:´tiliti] n.肥沃；多产；繁殖力 (英语六级单词)