Three things are at work here:

1. The big difference is that IHDS 1 is monthly per capita and IHDS 2 is annual. The IHDS 2 variable will be changed back to monthly during the next data update.

2. Price changes: There is a variable, DEFLATOR, in the public IHDS 2 file; mean= .5453441 .

3. Economic growth.

For example, take the mean above for IHDS 1: 955.09 multiply by 12 months and divide by the average IHDS 2 deflator, .5453441=21,016. The difference between 21,016 for IHDS-I and 27,155 for IHDS 2 is a measure of economic growth.

*Cautious* inferences can be made at the state level for large states (or state groups as in stateid2); but not at the district level. The issue is not so much weighting but sample size and selection. The urban sample is representative only at the state level; the rural sample might be considered more representative at the district (1991 district) level; but sample sizes are small so drawing conclusions about any one district would be mistaken. Samples sizes at the state level are also small sometimes, so *cautious* inferences are necessary. 

No. While IHDS 2 follows the same general pattern as IHDS 1 and many of the questions are identical, some questions were changed based on our experience with IHDS 1. Moreover, question numbers and variable names have also changed. Users are urged to consult the two sets of questionnaires and compare the question wording before trying to interpret the results.

If you look at the questionnaire you will see that birth date is collection in 4 columns, first two are month and second two years. So 497 would be month 04 and year 97.

Please pay attention to the questionnaires for each variable of interest. You may find in other cases (e.g. age of child at the moment) the question was asked age in years and months. So 1606 would 16 years and 6 months. Leading 0s are dropped, trailing are not.

Also 88 reflects missing value for months and 18 is missing value for calendar years.

WT — Sample weight for the household, most useful and usually used in almost all analyses

FWT — Integer weight (truncated from WT) for STATA routines that require integer weight

INDWT — WT * NPERSONS — this represents number of individuals in the household for analyses that require individual specific weights (e.g. Head Count Ratio for Poverty) when using the household-level file

INDFWT - integer value of INDWT.

(**Also pertains to the smoking, chewing tobacco and drinking variables in both surveys.)

Questionnaires were designed to reduce respondent burden. Hence at the start of the section, interviewers record the names of the respondents who engage in the activity or have the illness. Those who do not are coded as missing so as to excuse them from further questions.

Human Development in India citation:

Desai, Sonalde, Amaresh Dubey, B.L. Joshi, Mitali Sen, Abusaleh Shariff and Reeve Vanneman. 2010. Human Development in India: Challenges for a Society in Transition. New Delhi: Oxford University Press. Pp. 234.

IHDS I Citation:

Please go to the IHDS website HDPI page. Under this page there is a link page 'HDPI panel description and data use agreement". Complete the agreement information and send to ihdsinfo@gmail.com; once approved we shall send the link for downloading HDPI data sets.  This process can take up to two weeks.

Unfortunately we are not allowed under the terms of our ethical clearance guidelines to provide any geographic information below the level of the district. We seek to create a unique public resource of panel data for researchers interested in India. However, we must balance research needs with protecting the privacy of the respondents. Thus we had a choice of limiting individual information such as caste/religion and other background data that make individuals identifiable within a small village/neighborhood or limiting village/tehsil names and locations from our public release files.

Is IHDS a panel survey? If so, can I link IHDS 1 files with IHDS 2 files? What is required for linking?