What is the difference between -impute- and -reg- followed by
-predict-?
For example:
. impute t_aflcio_mem temp year if inrange(year,1956,2005),
g(i_aflcio_mem)
44.00% (22) observations imputed
. quietly reg t_aflcio_mem temp year if inrange(year,1956,2005)
. predict yhat if inrange(year,1956,2005)
(option xb assumed; fitted values)
(77 missing values generated)
. list year i_aflcio_mem yhat in 77/87
+----------------------------+
| year i_aflc~m yhat |
|----------------------------|
77. | 1956 15707.5 14748.04 |
78. | 1957 15965.1 15062.62 |
79. | 1958 13849.3 14816.2 |
80. | 1959 13701.4 14569.78 |
81. | 1960 13866.6 14336.76 |
|----------------------------|
82. | 1961 13618.2 14103.74 |
83. | 1962 13784.8 14021.69 |
84. | 1963 13904.2 13939.65 |
85. | 1964 14235.3 14286.39 |
86. | 1965 14815.9 14633.13 |
|----------------------------|
87. | 1966 15372.1 15372.03 |
. pwcorr yhat i_aflcio_mem
| yhat i_aflc~m
-------------+------------------
yhat | 1.0000
i_aflcio_mem | 0.8947 1.0000
OK, so the reg prediction and imputation differ, but why? -eret li-
indicates that -impute- is -regress-.
Thanks!
Caleb
[email protected]
University of Oregon Sociology
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