Estimation of polynomial regression equations in one error-ridden variable and a number of error-free regressors, as well as an instrument set for the former is considered. Procedures for identification, operating on moments up to a certain order, are elaborated for single- and multi-equation...

How are substitution in the spatial and in the temporal sense connected? Can estimates based on data with spatial variation be transmitted into values appropriate for exploring temporal variation, and vice versa? This paper, building on, inter alia, Frisch (1959), attempts to give some...

We consider a framework for analyzing panel data characterized by: (i) a system of regressions equations, (ii) random individual heterogeneity in both intercepts and slope coefficients, and (iii) unbalanced panel data, i.e., panel data where the individual time series have unequal length. A...

For a balanced panel data regression model with random effects, we discuss the efficiency of the GLS estimator relative to the OLS, the between, and the within estimators. Focus is on how the efficiency responds to changes in (a) the relative variance components and (b) the composition of the...

We discuss the relationship between the retirement process of the capital, as formalized by its survival function, and the average retirement rate, and how this relationship is affected by changes in the investment path. The effect of the survival function on the age distribution of the capital...

Drug abuse inflicts considerable harm on users, non-using persons and on society, and a variety of means to curtail consumption of illegal drugs have been adopted. The consumption of drugs differ from consumption of most other goods in that it involves addiction. Inter-temporal models are needed...

Farm couples' labour market responses are partly the qualitative choice of entering the ff-farm labour market and partly the continuous choice of the number of on-farm and off-farm working hours, given entry. Such a setting is interesting when examining the increasing occurrence of multiple...

In this paper, we consider the formulation and estimation of systems of regression equations with random individual effects in the intercept terms from unbalanced panel data, i.e., panel data where the individual time series have unequal length. Generalized Least Squares (GLS) estimation and...

Parametric aggregation of heterogeneous micro production technologies is discussed. A four-factor Cobb-Douglas function with normally distributed firm specific coefficients and with log-normal inputs (which agrees well with the available data) is speciffied. Since, if the number of micro units...

For a random effects regression model with unbalanced panel data, we demonstrate that the Generalized Least Squares (GLS) estimator can be expressed as a (matrix) weighted average of estimators which utilize the within individual and the between individual variation in the data set. We thus...