Vitamin D. a dynamic molecule. how relevant might the dynamism for a vitamin be

Cholecalciferol, the precursor of Vitamin D3, is a very old, highly conserved, molecule. Its presence is evident in non-mineralized 750 million-year-old living species, such as plankton. The more active metabolites, a receptor and a D binding protein, appear later, along with the increasing complexity of animal species living in the sea. In the sea, however, the biological function of vitamin D is unlikely to be linked with mineral metabolism, and we can hypothesize a relationship with an immune response. It is in terrestrial animals exhibiting cellular bone that the complexity of vitamin D increases. At this stage of evolution, we see the appearance of bone cells that are capable of producing hormones that regulate and are regulated by vitamin D. This interaction starts a sophisticated metabolic system that modulates both mineral and energy metabolism for the requirements of the musculoskeletal system. Among the so-called pleiotropic effects of vitamin D, those resulting from the inhibitory effect on the renin-angiotensin system are of particular interest for nephrologists. Intriguingly, however, more than for anti-hypertensive effects, this interaction could be relevant for anti-inflammatory actions, possibly representative of a residual ancestral role of vitamin D. In addition, this evolutionary dynamism of the vitamin D system should not be separated from the chemical dynamism that characterizes the ligand molecule and its specific receptor. Both are capable of significant tridimensional modifications that contribute to an increase in the variability and the partial predictability of their final biological effect. A dynamic overview of this system that takes into account its evolutionary and adaptive aspects may be helpful to understand its biological complexity and to envisage why using vitamin D metabolites for therapeutic purposes is still a matter of debate

Differential Mortality and Redistribution in the Italian Notional Defined Contribution System

In this paper we assess, through a financial measure (Net Present Value Ratio), the extent of the lifetime earning redistribution operated by the Notional Defined Contribution in a sample of individuals representative of the Italian population born from 1975 to 2000. Controlling mortality by the level of education we identify at least three channels of redistribution: among genders (from men to women), along educational lines (from low to high educated) and among income quintiles (from poor to rich). This happens because some groups systematically live less than average (men, loweducated and poor) while others live more than average (women, high educated and rich). This finding is not trivial: even if the NDC system assure long term financial sustainability, it harms the most disadvantaged groups like poor and low-educated people.Social security; Notional Defined Contribution; Italy

Pension reforms, educational choices and the long term dynamic of employment in Italy

In this paper we use CAPP_DYN, a population based dynamic microsimulation model to simulate the Italian employed population during the period 2005-2050. We find that the more interesting changes will affect the composition rather than the level of the employed population. We investigate main factors that are at work (cohorts effects, educational choices and pension reforms). Finally we present some sensitivity analyses to test our results with respect to different hypotheses regarding the future legal retirement age.

The Effects of Social Security on the Distribution of Wealth in Italy

The degree of substitutability between social security wealth and private wealth is a much-debated topic; however, less time and energy has been devoted to the study of the distributive properties of a measure of wealth summing future pension benefits net of contributions to the other traditional components of households’ net worth (financial and real activities, net of liabilities). The present paper has two essential aims: by using six cross-sections of the Bank of Italy’s Survey of Income and Wealth (1991, 1993, 1995, 1998, 2000 and 2002), it firstly aims to estimate an “augmented” measure of net worth incorporating social security wealth, and secondly it examines the composition and distribution of such augmented wealth among Italian households during the period 1991-2002. The result is that augmented wealth is found to have remained constant in real term over the last decade due to two opposing forces, namely an increase in net worth and a parallel, stronger decline in social security wealth, resulting from the two main pension reforms implemented in 1992 and 1995. Wealth inequality, after rising steeply at the beginning of the 1990s, levelled off during the second part of the period in question. The major contribution towards this upwards movement came from social security wealth, the distribution of which, although less unequal than that of real wealth and financial wealth, widened at a much faster pace at the beginning of the decade.

The effects of social security on the distribution of wealth in Italy

The degree of substitutability between social security wealth and private wealth is a widely discussed topic. Much less effort is devoted to study the distributive properties of a measure of wealth which sums the future streams of pension benefits net of the contributions to the other traditional components of households net worth (financial and real activities, net of liabilities). This paper has two aims. By using the last six crosssections of the Bank of Italy Survey of Income and Wealth, firstly it estimates an “augmented” measure of net worth which incorporates social security wealth, and secondly it examines the composition and the distribution of such augmented wealth among Italian households in the period 1991-2002. Augmented wealth is found to have fallen in the last decade as a product of two opposite forces, an increase in net worth and a parallel stronger decline in social security wealth, due to the two main pension reforms in 1992 and 1995. Wealth inequality, after rising steeply at the beginning of the 1990s, levelled off in the second part of the period. The major contribution to the upwards movement mainly came from social security wealth, whose distribution, although less unequal than the real and financial one, widened in the first part of the decade at a much faster pace.Social security wealth; Wealth distrubution; Wealth inequality; Italy

CAPP_DYN: A Dynamic Microsimulation Model for the Italian Social Security System

We present the technical structure of CAPP_DYN, a population based dynamic microsimulation model for the analysis of long term redistributive effects of social policies, developed at CAPP (Centro di Analisi delle Politiche Pubbliche) to study the intergenerational and the intragenerational redistributive effects of reforms in the social security system. The model simulates probabilistically the socio-demographic and economic evolution of a representative sample of the Italian population for the period 2005-2050. After a short review of the existing similar models for the Italian economy, a rather detailed analysis and discussion of the functioning of the model as well as a description of estimation procedures employed in each single module of the models is offered.Dynamic microsimulation; lifetime and intragenerational redistribution; social security systems

CAPP_DYN: A Dynamic Microsimulation Model for the Italian Social Security System

Microsimulation allows to apply a set of deterministic or stochastic rules on a sample of micro-unit such as individuals, households, .rms or institutions. A Dynamic Microsimulation Model (DMM) contains a set of rules aiming at projecting the likely socio-economic evolution of a representative sample of individuals throughout time. In this paper, we describe the simulation algorithms and the econom(etr)ic frameworks used in CAPP DYN, a population based DMM for the analysis of the inter- and intra-generational redistributive e.ects of the Italian social security system. By including detailed rules that determine the eligibility to various social security bene.ts, CAPP DYN is quali.ed as a useful tool in assessing the long-run distributional e.ects of the reforms approved in the Italian social security system.Dynamic Microsimulation; Pensions; Long-term care

The strengths and failures of incentive mechanisms in notional defined contribution pension systems

Public pension systems based on the Notional Defined Contribution (NDC) principle were introduced during the ‘90s in Italy, Sweden and Poland, among other countries. They mimic private savings, in that individuals get back, as pensioners, what they contributed to social security during working life, plus returns. As such, NDC systems should realize actuarial equity and incentive neutrality. However, when one considers the presence of NDC pensions together with minimum and social assistance pensions, this is no longer true. Indeed, in all the three countries considered, the NDC system shows a regressive feature, which disincentivizes contributions, particularly from low earners, who would be better off entering, or staying in, the shadow economy. In order to reduce the extent of this phenomenon, we examine the effects of introducing, or increasing, the possibility of accumulation of social assistance and NDC pensions, which would also improve pension adequacy. A complete accumulation of the two would solve the incentive problem, but would be costly and would require a structural reform of the pension system financing mechanism, altering the current balance between social contributions and general fiscal revenues. We show the effects of a change in the cumulation rules for social assistance and NDC pensions in Italy using CAPP_DYN, a population-based dynamic microsimulation model, which allows assessment of the evolution of the pension system in the coming decades and the distributional implications of such reform.

Modelling Private Wealth Accumulation and Spend-down in the Italian Microsimulation Model CAPP_DYN: A Life-Cycle Approach

In microsimulation literature a limited number of models include a module aimed at analyzing and projecting the evolution of privat e wealth over time. However, this issue appears crucial in order to comprehensively evaluate the li kely distributional effects of institutional reforms adopted to cope with population ageing. In this work we describe the implementation in the Italian dynamic micro simulation model CAPP_DYN of a new module in which households\u2019 savings and asset allocation are modelled. In parti cular, we aim to account for possible behavioural responses to pension reforms in househo ld savings. To this end, we rely on an approximate life cycle structural framework for est imating saving behaviour, while adopting a traditional stochastic micro simulation approach fo r asset allocation. In line with Ando and Nicoletti Altimari (2004), we emphasize the role of lifetime economic resources in households\u2019 consumption decisions, yet we further account for i nternal habit formation and subjective expectations on pension outcomes in the econometric stage. In addition, we model intergenerational transfers of private wealth in a probabilistic fashio