Minimal sample size for testing trinomial proportions for given precision of probability of type I error
format: Article | STATISTICA & APPLICAZIONI - 2013 - 1
The determination of sample size is a common task for many organizational researchers. Inappropriate, inadequate or excessive sample size continues to influence the quality, accuracy and costs of research. Sample size is one of the features of analysis that can influence the detection of significant differences for population so we can’t ignore problem of sample size. This paper presents a procedure and a table for selecting sample size for simultaneously testing the parameters of a trinomial distribution. The results are obtained by examining the several possible value of a trinomial parameter vector and comparing the fixed first error type with the empirical one obtained by building the exact distribution through the code R.
Redistribution and equity of polish personal income tax: measurement using micro data from tax returns
format: Article | STATISTICA & APPLICAZIONI - 2009 - 2
The redistribution effect of taxation is widely analyzed in literature. General findings could be summarized as follows: actual redistribution depends both on construction of tax schedule and unintended effects, such as reranking of incomes, caused by taxation. To separate both components, several decompositions of redistribution index have been described. In this paper, authors analyze decomposition proposed by Kakwani and Lambert (1998), who describe three principles of tax equity and three related measures of inequity. Authors apply outcomes of this decomposition in quest for the equivalence scale that implicitly results from the construction of tax system. Taking into account decomposition outcomes and the implicit equivalence scale found, we try to assess inequity of Polish income tax system in the context of its welfare consequences. All analyses are made basing on data from revenue offices and Central Statistical Office. Keywords: decomposition of redistribution index, welfare, taxation.