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Summary of Changes to 1999 AHS Data

The Problem:

A processing error was discovered which affected the 1999 data. In every 1999 case where we had a valid entry in the 1997 survey we over wrote the 1999 answer with the 1997 answer for the variables WHNGET, FRSTOC, CUSHOM, PREOCC, LPRICE, CPRICE, DWNPAY AND FRSTHO. We were ONLY suppose to take the 1997 answer if we had the same housing unit and household in 1999. These restrictions were not applied. The 1997 answer was taken even if we were dealing with a different housing unit and/or household. The new micro data public use file (PUF) corrects this problem.

Results of Correction:

The data for the following owner occupied variables, all from the Real Estate Transaction (RET module) were purposely changed as a result of this correction.


The changes in the data for these variables were significant, especially the changes to WHNGET. Any previous analysis done using these variables should be redone.

The data for the following owner occupied variables also changed. Changes in these variables where relatively minor. Previous analysis using these variables would most likely not change. All are from the mortgage module. The changes in these variables were the result of edits in the mortgage module which depended on the data in the above mentioned purposely changed RET variables (in most cases the variable WHNGET). These variables include.


The following is a list of publication (from the 1999 H-150 publication) owner occupied items and recodes that change as a result of variable changes mentioned above. Beside each item is listed the variables causing the differences in the data along with an assessment of the severity of the change. Minor means that any previous analysis using these data should not be affected using the new data. Significant means that the differences appear to be statistically significantly and that overall analysis using these data may be affected. Major means that any previously done analysis using the old data will be affected should be redone using the new data.

Monthly Housing Costs-due to PMT and PMT2 changes---Minor.

Monthly Housing Costs as Percent of Current Income-due to PMT and PMT2 changes--Minor.

Previous Occupancy-due to changes in FRSTOC-Minor.

Monthly Payment for Principal and Interest-due to changes in PMT and PMT2-Minor.

Year Unit Acquired-due to changes in WHNGET-Major.

First Time Owners-due to changes in FRSTHO-Significant.

Purchase Price-due to changes in CUSHOM PREOCC CPRICE LPRICE-Significant.

Major Source of Down Payment-due to changes in CUSHOM PREOCC DWNPY-Significant.

Mortgage Origination-due to changes in MATBUY - Minor.

Year Primary Mortgage Originated-due to changes in MATBUY, YRMOR and WHNGET-Major.

Term of Primary Mortgage at Origination or Assumption-due to changes in TERM-Minor.

Remaining Years Mortgaged-due to changes in MATBUY, TERM, WHNGET, YRMOR-Minor.

Current Interest Rate-All the changed mortgage variables except for PMT and PMT2 go into this recode-Significant.

Total Outstanding Principal Amount-All the changed mortgage variables except for PMT and PMT2 go into this recode-Significant.

Current Total Loan as Percent of Value-All the changed mortgage variables except for PMT and PMT2 go into this recode-Minor.

Source: U.S. Census Bureau | American Housing Survey (AHS) |  Last Revised: 2012-12-11T12:34:21.945-05:00