1.1. El DISTRITO ECONÓMICO MARBELLA-ESTEPONA
1.1.1. Justificación del distrito como ámbito de estudio
In order to carry out the simulations for the analysis phases of this project, we needed the relevant data (for target variables and covariates) on the population. In the course of constructing realistic pseudo-population, we drew on model-based techniques similar to those that we use for the estimation itself. It was the key idea in EURAREA approach. We constructed pseudo-population based on joined databases obtained from the Ministry of Finance (tax register) and CSO (BJS). To do so, we had to apply an imputation of the data. We tested two possibilities: linear and logarithmic regression. However, simulation studies turned out to be unsatisfactory. MSEs of seven standard estimators were large, quite often we obtained negative or extremely large estimates.
In view of the stratified sampling used in the study, it was necessary to modify the EURAREA programme to account for sample weights. The change involved giving up the simulation-based approach since no pseudo-population was created and the estimation was calculated for one sample only, which was the result of the SP3 survey of 2001. Under these circumstances, it was not possible to calculate empirical measures of estimation precision. Direct estimator variance was estimated for domains treated as strata and for the synthetic estimator of regression and the EBLUP estimator a simplified approach was applied.
Conclusions
•
The Center of Regional Statistics was the first institution in Poland to attempt indirect estimation in small business statistics in Poland. The preliminary results are encouraging but require more adequate assessment. It would be risky at this stage to make them available as a final outcome to a wider group of users. The experimental character of the study was also due to its first-time application of data from both the SP-3 survey and the administrative (tax) register but only for the year 2001. The tax register was used as a source of covariate data.•
Among the 7 estimators under consideration, the best results were obtained using the synthetic and GREG estimators. The other estimators yielded results that were clearly incompatible with what we knew about economic reality.•
Our attempt at applying the EURAREA approach involving a pseudo-population and estimator validation by means of the Monte Carlo method cannot be regarded as successful. Further research to be carried out in the future, drawing on experiences collected in Western countries with better statistical infrastructure and relying on methodologies more suited to handling economic data should produce more satisfying results.1. It is impossible to apply automatically the experiences gained during the EURAREA project in micro enterprise statistics.
•
The asymmetry of distributions for basic variables describing enterprises (revenues, costs, wages and number of employees) made it impossible to use the approach based on pseudopopulation. This is why empirical estimation of variance (mean squared error) could not be applied.•
One can expect an improvement in estimation precision for small domains when analysts gain access to tax registers for consecutive years to enrich the pool of auxiliary variables. With respect to individual micro-enterprises, a similar positive effect can be expected after analysing different types of entities in the tax register and accounting for null values and self-employed.•
The problems we faced and experiences gained should not result interminating the work on finding more adequate methods for enterprise statistics than the ones applied in the EURAREA project. It should be so especially because there are reasons for building econometric models based on many more covariates than we had. These covariates could be enterprise characteristics for several periods of time.
1 see Heldi et al. (2001), Estevao, Hidiroglou, Särndal (1995), Karlberg (2000), Särndal, Lundström (2005)
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