Modified Kuppuswamy scale for socioeconomic status of the Indian family- Update based on New CPI (IW) series from September 2020

Dear Sir,

The article titled “Socioeconomic status scales-modified Kuppuswamy and Udai Pareekh's scale updated for 2019” published on June 2019 in the esteemed journal of Family Medicine and Primary Care is a well written one.[1] In the field of Family medicine, Socio-Economic Status is one of the most important determinants of health status of the family. The researchers in the field of family medicine and primary care should be updated with regards to the income limits for classification of socio-economic status. Kuppuswamy SES scale and its modifications used both in urban and rural areas, is based on 3 variables – Monthly total family income, Occupation and Education of the head of the Family.[2] This scale focuses on the Total Monthly family income as a whole in the determination of socio-economic status compared to other scales such as BG Prasad scale, which focus on Per capita monthly income. As pointed out in the article,[1] there was a need for update in the base year of All India Consumer Price Index (CPI) for Industrial workers (IW) from 2001 series. Recently, the Labour Bureau, government of India has revised the base year of the existing CPI-IW series from 2001 = 100 to a more recent, 2016 = 100 in October 2020.[3,4] The aim of this letter is to update the income ranges for Modified Kuppuswamy scale based on the recently released All India CPI-IW with 2016 as baseline (=100).[3] As shown in Table 1, the baseline year was used as 2001 (=100), prior to the current release.[4] The Labour Bureau, government of India on monthly basis releases the CPI-IW, which in turn decides the income limits.

Table 1.

All India Consumer price index for Industrial Workers from January 2016 to September 2020- CPI (IW): Base 2001=100

Year	January	February	March	April	May	June	July	August	September	October	November	December
2020	330	328	326	329	330	332	336	338	340*
2019	307	307	309	312	314	316	319	320	322	325	328	330
2018	288	287	287	288	289	291	301	301	301	302	302	301
2017	274	274	275	277	278	280	285	285	285	287	288	286
2016	269	267	268	271	275	277	280	278	277	278	277	275

*Sept 2020 CPI (IW)=118 with Base 2016=100, Linking factor for 2016 (100) = 2001 (100) × 2.88.[3,4,5] Source: Labour Bureau, Ministry of Labour and Employment, Government of India.[3,4,5]

Table 1 shows the CPI (IW) from January 2016 to September 2020. The old baseline, 2001 (=100) was used till the month of august 2020. New baseline series, 2016 (=100) has been adapted for the month of September 2020.[3] The linking factor between the old (2001) and new series (2016) is 2.88.[5] CPI (IW) for September 2020 with 2016 (=100) as baseline is 118.[3] Using these value, the CPI (IW) for September 2020 was 340 as shown in Table 1 with 2001 (=100) as baseline. That is if the old baseline had been used, the CPI (IW) for September 2020 would be 340.

Table 2 shows the updated income limits of Modified Kuppuswamy scale for September 2020 derived from Baseline 2001 limits as derived by Wani RT (2019).[1] Calculation of 2016 baseline limits are essential for future use as multiplication factor has to be applied to this baseline till the next baseline year for CPI (IW) is announced. This may be atleast 5 years away as planned by the Labour Bureau, Government of India. Table 2 describes the method of calculation used for calculating the income limits for Modified Kuppuswamy scale using the various linking factors.

Table 2.

Modified Kuppuswamy scale total monthly family income limits updated for September 2020 in rupees

Score	Original monthly income limits2 (1976)	Total monthly family income limits1 (2001 as Base year)	Total monthly family income limits (2016 as Base year) Multiplication factor=2.88	Total monthly family income limits for September 2020 With 2016 (=100) Multiplication factor=1.18
12	2000 and above	15,197 and above	43,767 and above	51,646 and above
10	1000-1999	7,595-15,196	21,873-43,766	25.811-51,645
6	750-999	5,694-7,594	16,399-21,872	19,351-25,809
4	500-749	3,793-5,693	10,924-16,398	12,890-19,350
3	300-499	2,273-3,792	6,546-10,923	7725-12,889
2	101-299	761-2,272	2,192-6,545	2586-7724
1	100 and below	760 and below	≤2191	≤2585

Due to rounding off and multiplying factors applied for upper limits, the lower limits for each category will be only approximate. Source: 1. 1976 limits from Original kuppuswamy scale.[1] 2. 2001 limits as calculated by Wani RT.[2] 3. Linking factors from Labour Bureau, Ministry of Labour and Employment, Government of India.[3,4,5]

2020 September CPI (IW) = 118 (with Base 2016 = 100).[3,4]

Total Family monthly income limits (2016) = 2001 value × 2.88[4,5]

Total Family monthly income limits (September 2020) = 2016 value × 1.18[3,4]

This updated Modified Kuppuswamy scale will help the researchers to update the income limits while applying it in their day to day research. By applying their state and month specific values of CPI (IW) updated regularly on the last working day, of the succeeding month, researchers can improve the validity of the Socio-economic status of the family.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.