TABLE 4 IV Estimates (1) (2) (3) Variable 2SLS LIML
2SLS ln(community size) -16.
Los resultados de la segunda etapa (cuadro 7) muestran que las regresiones de MC2E son identicas a las regresiones LIML
, de modo que no hay problemas de sobreidentificacion de la regresion de MC y se puede confiar en sus resultados.
1]) and has a convex behavior with the turning point at the middle interval for 2SLS, LIML
and 3SLS at N = 25 and N = 40 respectively.
P-value refers to conditional p-value estimated by LIML
Note that the LIML
model is not subject to the "forbidden regression" issue--where predicted values from a first stage are inappropriately inserted into a nonlinear second stage discussed in Wooldridge (2002, p.
The identity is another structural relation and its role is important in the distribution theory because it provides a magnet for an alternative centering, pulling consistent estimators like IV and LIML
away from the relevant parameter in the behavioral relation and thereby naturally inducing a bimodality.
For 2SLS and LIML
models, the instruments used to identify the drug variables are DEPEND, number of dependents may create stress, ILL, RELIGION, which has consistently been found to be a negative predictor of drug use, all used exclusively and common instruments - TEMP and SCON.
EBSE UENEQ VIEH LEIV NEYHO UPRES TIMES EMARF ORDOB BXO KOMSRE NTISG WSRAM NANINGC EZERFGNI YIDRNG RASJ ROTARDYHED NIRAG LIML
DISL SERPERUS ROKOEC
Fuller version of the IV method is robust to weak instruments.
is useful because it has the same asymptotic distribution as 2SLS, yet provides a finite-sample reduction in bias.
The empirical results gave strong support to the new econometric methodology in terms of the plausibility of the LIML
coefficient estimates and the performance of the fitted equations in post-sample predictions in comparison with least squares.
I then present the LIML
estimates and compare them to the IV estimates.