Papers in deze reeks gaan over methoden, processen en informatietechnologische- en conceptuele onderwerpen die relevant zijn voor het werkterrein van het CBS. Ze beschrijven het resultaat van (toegepast) wetenschappelijk onderzoek dat CBS-ers, al dan niet samen met externen, hebben uitgevoerd. De reeks is niet bedoeld om CBS-cijfers te publiceren en de cijfers in de papers zijn dus niet als officiële CBS-uitkomsten aan te merken. De papers verschijnen onregelmatig. U kunt een gratis e-mail-abonnement op de reeks nemen.
20-12-2005
An inventory was made of methods used in longitudinal analysis by National Statistical Institutes, together with selected longitudinal data sets of NSI's. The methodology was mostly not an explicit of these studies. The UK, the USA, Canada, and New Zealand have a long tradition of longitudinal surveys. Sweden and Denmark have longitudinal possibilities based on registers. Most studies concern persons, rather than enterprises. Statistics Netherlands has five longitudinal surveys and several longitudinal registers.
21-11-2005
This paper relates unemployment outcomes from the Dutch labour force survey to the number of individuals registered at Dutch employment offices. Both series evolve rather similar, despite the substantial differences in underlying populations. The empirical relationship is quantified with a state space model. This model is subsequently used to generate forecasts for the unemployed labour force. By comparing the forecasted values with survey outcomes, outliers can be identified.
19-10-2005
In this paper we present how we can measure directly continuous creation and destruction flows for emplyee jobs from the Social Statistical Database (SSD), and how the flows are related with the quantity of jobs and average number of jobs in a year. Furthermore we suggest some indicators for the study of continuous job flow dynamics between years and subpopulations.
29-09-2005
Using a classification method developed in this paper, the quality of qualitative survey data of the manufacturing industry at micro-economic level is investigated. For single companies, recent opinions on recent production developments are compared to quantitative results of industrial turnover. The results show that 57.6% of the analyzed companies give useful qualitative answers for calculating meaningful balance statistics such as producers’ confidence. The level of agreement between quantitative and qualitative data for companies with seasonal patterns in turnover on average is 10.6%-points higher than for companies without seasonal patterns.
23-09-2005
This paper investigates the noncoverage bias in CATI-surveys. This bias is introduced by the restriction of using the telephone as a communication medium. Obviously, only that part of the population that disposes of a listed, fixed-line telephone can be interviewed by means of CATI.. Data from a CAPI-survey, the Integrated Survey of Living Conditions, is used to assess the noncoverage bias when restricting the sample to individuals that own a listed, fixed-line telephone.Individuals with and without a listed, fixed-line number are compared. Two methods to adjust for the noncoverage bias are applied to the data from the Integrated Survey of Living Conditions: linear weighting and propensity score stratification. Finally, a strategy is explored to simultaneously adjust for nonresponse and noncoverage bias.
09-09-2005
According to the System of National Accounts (SNA 1993) illegal activities should be registered in the national accounts, as the accounts should cover all economic activities, including those deliberately concealed from the authorities. Illegal production concerns activities which generate goods and services which themselves are forbidden by law, or activities that are illegal when performed by unauthorised persons. In this paper, illegal activities, as for example drugs related activities, in the Netherlands are described and an estimate of their contribution to the Dutch economy in 2001 is presented. The estimates in this report are not based on official statistics.
16-08-2005
In this paper, the stace space approach is used to perform temporal disaggregation. The investigation is performed in two steps. In the first step, the state space approach is tested on two study cases in order to investigate the accuracy of the temporal disaggregation. In the second step, the method is applied to the retail sales statistics in order to obtain estimates for the monthly turnover of the retail sector. The paper concludes that the combination of the state space approach and Denton’s adjustment method of monthly or quarterly series to annual totals provides a powerful tool to disaggregate annual data into higher frequency series.
16-08-2005
Now that the Internet is expanding so rapidly, it has become an attractive medium for collecting relatively large amounts of data in a relatively cheap way. Not surprisingly, national statistical institutes, research institutes, and commercial marketing research organisations are using, or are considering using, Internet surveys for collecting survey data. However, use of Internet surveys is not without draw-backs. Lack of attention for the methodological aspects may easily lead to survey designs that will produce invalid survey results. And there are ample examples of such surveys. This paper gives a description of some of the methodological problems of Internet surveys. Then it discusses the role web surveys can play in national statistical institutes. In the short run, Statistics Netherlands foresees interesting applications in mixed-mode surveys Attention is paid to some problems concerning implementation of mixed-mode surveys. The Blaise system, developed by Statistics Netherlands, is described as a useful tool for mixed-mode surveys. Some early experiments and experiences with Internet surveys are mentioned. The final part discusses the prospects for single-mode Internet survey in the not too far away future.
08-06-2005
Nonresponse in household surveys can be a threat to the quality of statistics. Research shows that often the response to these surveys is selective with respect to demographic characteristics like age and household composition. For this reason estimators are usually adjusted to account for nonresponse.Nonresponse adjustment methods make use of covariates that are available for both respondents and non-respondents. A problem is the selection of covariates that relate both to the key survey questions and to the response behaviour. Therefore, often the process of selection is performed in two steps.We present a classification tree method that allows for the construction of weighting strata that simultaneously account for the relation between response behaviour, survey questions and covariates. We apply the classification trees to survey data of Statistics Netherlands.
01-03-2005
The objective of the research described in this paper is to improve the quality of the statistics of the turnover growth of the manufacturing industry. The quality parameters studied are timeliness and accuracy. Without adaptations of the compilation process of the statistics, improvement of one parameter will usually lead to a deterioration of the other. Three approaches are explored. The first approach considers alternative imputation methods for non-response. Methods can be found which improve timeliness with one week without loss of accuracy. The second approach is selective response chasing of the largest enterprises, which also seems quite promising. The third approach combines early response with an expected value or "nowcast". It improves the accuracy of the estimation of the turnover growth during the first 3 weeks after the reference month, however not enough for a timelier publication.