National Sample Survey (India)
National Sample Survey (India)
The National Sample Survey (NSS) is one of the oldest continuing household sample surveys in the developing world. The survey is conducted on a regular basis by the National Sample Survey Organisation (NSSO), India’s premier data collection agency. Since 1972, the NSSO has fallen under the Ministry of Statistics and Program Implementation of the Government of India (GOI).
The role of the NSS must be seen in the broader context of Indian economic development. At independence and through much of its early development, the country was faced with a subsistence production structure (mainly in agriculture) characterized by mass poverty and hunger. Systematic data on the extent, magnitude, and patterns of poverty, as well as on household consumption patterns and trends, were not readily available for informed policy interventions. To remedy this, the GOI launched the NSS to gather nationally representative information on household structure, consumption, and production.
The first NSS round was conducted in1950–1951and included information on land utilization, prices of essential commodities, and daily wages of skilled and unskilled laborers at the village level. At the household level, data was obtained on demographic characteristics as well as land ownership, cultivation, and utilization. In addition, detailed data was gathered on monthly and weekly consumption, as well as on entrepreneurial activities, from a subset of the sampled households. The first round was based on a random sample of only 1,833 villages out of a total of 560,000.
Since that first round, more than sixty NSS rounds have been conducted. Naturally, both the organization and the surveys have undergone many changes since then. At the organizational level, the technical wing of the NSSO was divested from the Indian Statistical Institute and placed under the direct control of the GOI. The field operations group was placed under the guidance of a governing council headed by an eminent academic and members drawn both from government and academia since 1970; it now functions as a full-fledged wing of the GOI.
Important changes also occurred in the surveys themselves. With increased demand for more disaggregated information, the sample size of the rounds has expanded significantly, from 1,833 villages in the first round to more than 14,000 rural villages and urban blocks in more recent rounds. With the large increase in sample size, a decision was made (beginning with the1973–1974round) to split the rounds into two: quinquennial (or “thick”) rounds done at approximately five-year intervals on a large sample of households (about 120,000) and “thin” rounds undertaken during intervening periods on smaller samples (approximately 35 to 40 percent of the thick-round samples). The expansion of the sample size, especially for the collection of data on consumption expenditure and employment, has allowed NSS estimates to be representative at the below-state (but not district) level. The NSSO is representative at the level of regions— collections of several districts grouped together on the basis of broadly similar agro-climatic conditions. Regions are not administrative units. The NSS has delineated a total of seventy-eight regions in the country.
The coverage of the NSS varies over the different rounds. Each round always obtains information on consumption and employment; however, the rounds also cover other subjects, such as health, schooling, or disability, in the form of additional modules. Thus, for instance, the fifty-eighth round focused on disability, housing conditions, village facilities, and urban slums, while the sixtieth round covered morbidity, health care, and conditions of the elderly. Since its inception, the NSS has covered some fifty different subjects in its surveys, such as household debt and investment, literacy and culture, health, schooling, and village-level infrastructure.
Until 1998 the unit record data from the NSS was not available to the public. This restricted considerably the wider use of the surveys by researchers. Indeed, only a few studies were based on the NSS data, including the measurement of poverty and unemployment and the construction of price indices, such as those by Ahluwalia (1978), Bhattacharya et al. (1980), Jain and Tendulkar (1989, 1990), and Minhas et al. (1987, 1988). In 1998 the GOI made the NSS unit record data, retrospectively from the thirty-eighth round of 1983, available in the public domain at a modest fee. Since that time, numerous researchers have used the data to address a number of issues, such as health, nutrition, schooling, disability, small-scale industry, and food subsidies (Borah 2006; Deolalikar 2005; Gupta 2003; Subramanian and Deaton 1996). Poverty and, to a smaller extent, unemployment remain the two top issues that are explored by researchers with the NSS data (e.g., Datt 1999; Deaton and Dreze 2002; Dubey and Gangopadhyay 1998; Sen 2000; Sundaram 2001a, 2001b; Sundaram and Tendulkar 2001).
The NSS has sometimes changed its data collection methodology midstream, and this has affected the comparability of NSS estimates over time. This was particularly the case in the fifty-fifth round, when the NSS adopted a different reporting period for certain types of consumption expenditures, rendering consumption and poverty estimates from that survey noncomparable to those from earlier periods. Another weakness of the data is that, unlike some other national socioeconomic surveys (notably the National Socio-Economic Household Survey, or SUSENAS, of Indonesia), there is no fixed rotation schedule for the special-interest modules that are attached to the core consumption-employment module of the NSS. As a result, it is difficult to obtain nationally representative data on important topics such as health and education on a regular, ongoing basis. For instance, the NSS included a health-care module in the fifty-second round conducted in 1995–1996, but this was not repeated until the sixtieth round in 2004. Likewise, the topic of rural assets and indebtedness was covered in the forty-eighth round in 1992 and only revisited in 2003 in the fifty-ninth round. It would be helpful if a regular rotation schedule were established whereby important topics such as health, schooling, and assets could be covered every three or four years.
SEE ALSO National Family Health Surveys; National Longitudinal Survey of Youth; Panel Study of Income Dynamics
Ahluwalia, Montek S. 1978. Rural Poverty and Agricultural Performance in India. Journal of Development Studies 14 (3): 298–323.
Bardhan, Pranab K. 1974. The Pattern of Income Distribution in India: A Review. Sankhya C-36 (2): 103–138.
Bhattacharya, N., P.D. Joshi, and A.B. Roychoudhury. 1980. Regional Price Indices Based on NSS 25th Round Consumer Expenditure Data. Sarvekshana 3 (4): 107–121.
Borah, Bijan J. 2006. A Mixed Logit Model of Health Care Provider Choice: Analysis of NSS Data for Rural India. Health Economics 15 (9): 915–932.
Datt, Gaurav. 1999. Has Poverty Declined since Economic Reforms? Economic and Political Weekly, 34 (50): 3516–3518.
Deaton, Angus, and Jean Dreze. 2002. Poverty and Inequality in India: A Reexamination, Economic and Political Weekly, September 7: 3729–3748.
Deolalikar, Anil B. 2005. Attaining the Millennium Development Goals in India: Reducing Infant Mortality, Child Malnutrition, Gender Disparities and Hunger-Poverty and Increasing School Enrollment and Completion? New Delhi: Oxford University Press.
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Gupta, Indrani. 2003. Inequities in Health and Health Care in India: Can the Poor Hope for a Respite? Mimeo. New Delhi, India: Institute of Economic Growth.
Jain, L. R., and Suresh D. Tendulkar. 1989. Intertemporal and Interfractile-Group Movements in Real Levels of Living for Rural and Urban Population of India: 1970–1971 to 1983. Journal of Indian School of Political Economy 1: 313–334.
Jain, L. R., and Suresh D. Tendulkar. 1990. Role of Growth and Distribution in the Observed Change in Headcount Ratio Measure of Poverty: A Decomposition Exercise for India. Indian Economic Review 25 (2): 165–205.
Minhas, B. S., L. R. Jain, S. M. Kansal, and M. R. Saluja. 1987. On the Choice of Appropriate Consumer Price Indices and Data Sets for Estimating the Incidence of Poverty in India. Indian Economic Review 22 (1): 19–49.
Minhas, B. S., L. R. Jain, S. M. Kansal, and M. R. Saluja. 1988. Measurement of General Cost of Living for Urban India. Sarvekshana 12 (1): 1–23.
Sen, Abhijit. 2000. Estimates of Consumer Expenditure and Its Distribution. Economic and Political Weekly, December 16: 4499–4518.
Subramanian, Shankar, and Angus Deaton. 1996. The Demand for Food and Calories. Journal of Political Economy 104 (1): 133–162.
Sundaram, Krishnamurthy. 2001a. The Employment-Unemployment Situation in India in the 1990s: Some Results from the NSS 55th Round Survey. Economic and Political Weekly, March 17: 931–940.
Sundaram, Krishnamurthy. 2001b. Employment and Poverty in 1990s: Further Results from NSS 55th Round Employment-Unemployment Survey, 1999–2000. Economic and Political Weekly, August 11: 3039–3049.
Sundaram, Krishnamurthy, and Suresh Tendulkar. 2001. NASNSS Estimates of Private Consumption for Poverty Estimation: A Disaggregated Comparison for 1993–1994. Economic and Political Weekly, 36 (2): 119–129.
Sundaram, Krishnamurthy, and Suresh Tendulkar. 2003. Poverty Has Declined in the 1990s: A Resolution of the Comparability Problems in NSS Consumer Expenditure Data. Economic and Political Weekly, 38 (4): 327–337.
Anil B. Deolalikar