Modeling delay in diagnosis of NF: under reportincg,incidence and prevalence estimates

In this paper, we analyze data from the Italian National Register of Rare Diseases (NRRD) focusing, in particular, on the geo-temporal distribution of patients affected by neurofibromatosis type 1 (NF1, ICD9CM code 237.71). The aim is at deriving a corrected measure of incidence for the period 2007–2009 using a single source, and to provide NF1 prevalence estimates for the period 2001–2006 through the use of capture–recapture methods over two sources. In the first case, a reverse hazard estimator for the delay in diagnosis of NF1 is used to estimate the probability that a generic unit belonging to the population of interest has been registered by the archive of reference. For the second purpose, two-source capture–recapture methods have been used to estimate the number of NF1 prevalent units in Italy for the period 2001–2006, matching information provided by the NRRD and the national register of hospital discharge, Scheda di Dimissione Ospedaliera (in the following SDO), archives.     

A “Swedish” actuarial balance for a notional defined contribution pension scheme with disability and minimum pension benefits

This article proposes a “Swedish” type actuarial balance sheet (ABS) for a notional defined contribution (NDC) scheme with disability and minimum pension benefits. The proposed ABS splits the pension system in two parts: the pure NDC part and the redistributive part, which includes the assets and liabilities originating from non‐contributory rights. The article contains a numerical example that sheds light on the real applicability of our proposal. The model has practical implications that could be of interest to policy‐makers, given that it integrates actuarial and social aspects of public pensions and discloses the real cost of redistribution through minimum pensions.     

A “maximum node clustering” problem

In this note we introduce a graph problem, called Maximum Node Clustering (MNC). We prove that the problem (which is easily shown to be strongly NP-complete) can be approximated in polynomial time within a ratio arbitrarily close to 2. For the special case where the graph is a tree, the problem is NP-complete in the ordinary sense; for this case we present a pseudopolynomial algorithm based on dynamic programming, and a related Fully Polynomial Time Approximation Scheme (FPTAS). Also, the tree case is shown to be exactly solvable in time, where n is the number of nodes.     

The Redistributive Effects of the Tax Wedge in Italy

Abstract. This paper presents an original data set of microdata on the tax wedge in Italy, obtained by using the microsimulation model ITAXMOD, developed at ISPE (Institute for Studies on Economic Planning). These data are used to measure the components of the tax wedge and their burden on the total cost of labour at the individual level. The results have been aggregated across income brackets, socio-economic groups and sectors of employment. These data are the necessary preliminary input for any redistributive analysis and in addition they make the available data for Italy comparable with those of other countries. Scant attention has been paid up to now to the redistributive aspects of the tax wedge, since most analyses are based on the income of the “average production worker” which is far from an ideal standard for comparison. The computation of the tax wedge for different brackets of total labour cost has been explored in two ways. The first is related to the differing weights of the components of the tax wedge on cost of labour and no particular hypothesis has been made about the incidence of these components. The results show that the burden of personal income taxation and of social security contributions is very high even for wage-earners in the lowest brackets (in 1992, the estimated tax wedge is more than 44% of total labour cost even in the second decile of the labour cost). That might discourage both labour supply and labour demand across the entire spectrum of deciles of cost of labour. The second line of research studies the incidence of personal income taxes and employees' social security contributions on gross earnings, under the maintained hypothesis that these two components of the tax wedge are shouldered by the employees.