The aim of this work is to review the paper by Hellerstein & Imbens (1982) focusing on the use of auxiliary data and a formal derivation of the asymptotic properties of the underlying Weighted Least Squares estimator.

The debate over the economic effects of military spending continues to develop, with no consensus, but a deepening understanding of the issues and limitations of previous work. A recent survey has suggested that the inclusion of post Cold War data has tended to make finding a negative effect...

The following note proposes a simple procedure to estimate k parameters of interest in a linear model with potentially k conditionally endogenous variables of interest and m endogenous control variables in the presence of at least one instrumental variable under the assumption of conditional...

We show in this paper that the treatment of conditional heteroskedasticity inside nonlinear systems of simultaneous equations is a sufficiently manageable matter for some types of multivariate ARCH error structures. Reparameterization makes it possible to estimate the model by means of the...

In this paper, we extend Bai and Perron’s (1998, Econometrica, p.47-78) framework for multiple break testing to linear models estimated via Two Stage Least Squares (2SLS). Within our framework, the break points are estimated simultaneously with the regression parameters via minimization of the...

I reconsider various methods for correcting for bias in estimates of the returns to schooling. I argue that the literature on ability bias has ignored complications implicit in theoretical formulations of the choice of human capital. In particular, such models imply that adding ability to the...

IV estimators with an instrument vector composed only of past squared residuals, while applicable to the semi-strong ARCH(1) model, do not extend to the semi-strong GARCH(1,1) case because of underidentification. Augmenting the instrument vector with past residuals, however, renders traditional...

This paper gives a new jackknife estimator for instrumental variable inference with unknown heteroskedasticity. The estimator is derived by using a method of moments approach similar to the one that produces LIML in case of homoskedasticity. The estimator is symmetric in the endogenous variables...

Twin births are often used as an instrument for fertility in models investigating the impact of family size on labour market and child outcomes. However, a large share of twin births (24% in our sample) are the result of fertility treatments, potentially causing twin births to be endogenous and...