st: Imputing values from bracketed responses

[diebold@email.unc.edu]

Hello,

I have a data set where respondents were asked for continuous values 
for variables such as income.  If individuals were unsure of a specific 
value they were provided with intervals (0-10,000, 10,001-20,000, 
20,001-30,000...) and asked to select which interval best approximated 
their income.  I would like to replace these bracketed responses with 
continuous values.

My plan is to regress income on a set of covariates and obtain 
predicted values from the regression line.  I will then match 
respondents with continuous values to those with bracketed responses 
using these predicted values and impute the continuous value for the 
matched individual with a bracketed response.

First, is this a reasonable way to get continuous values from bracketed 
responses?

Second, what matching program would you recommend?

Third, after the match, what command should I use to tell Stata to 
impute the continuous value of the matched respondent for the 
individual with a bracketed response?

The diagram below is an example of what I am trying to accomplish.  
Where "income" are continuous value data, "incomeb" are bracketed 
responses, and "matchid" indicate the matched respondent for those with 
bracketed reponses.

id       income      incomeb     ystar      matchid   new income  1     
    12           .          12           .         12
2         15           .          14.5         .         15
3         35           .          38.25        .         35
4         42           .          44.5         .         42
5          .         10-15        10.75        1         12
6          .         30-40        37           3         35

In this instance, individuals are matched based on the predicted income 
"ystar" and I need to know a command that will allow me to put the 
income for respondent "1" for matched respondent "5" and the income for 
respondent "3" into matched respondent "6".  The "new income" variable 
is the result that I am hoping for in the end.

Thank you very much.
Jeff D


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