Upgrading investment regulations in second pillar pension systems : a proposal for Colombia

The passivity of the demand for pension products is one of the striking features of mandatory pension systems. Consequently, the provision of multiple investment alternatives to households (multifund schemes) does not ensure that contributions are invested efficiently. In addition, despite the theoretical findings that short term return maximization is not conductive to long-term return maximization, the regulatory framework of pension fund management companies puts excessive emphasis on short-term maximization. Therefore, it is not obvious that typical regulatory framework of pension funds is conductive to optimal pensions. By establishing a set of default options on investment portfolios, this paper proposes a mechanism to align the incentives of the pension fund management companies with the long-term objectives of the contributors. The paper provides a methodology, which is subsequently applied to Colombia.Debt Markets,Emerging Markets,Financial Literacy,Mutual Funds,Investment and Investment Climate

Variational estimates for the effective response and field statistics in thermoelastic composites with intra-phase property fluctuations

International audienceIn this work, variational estimates are provided for the macroscopic response, as well as for the first and second moments of the stress and strain fields, in thermoelastic composites with non-uniform distributions of the thermal stress and elastic moduli in the constituent phases. These estimates are obtained in terms of a 'comparison composite' with uniform phase properties depending on the first and second moments of a certain combination of the given intra-phase thermal stresses and modulus field distributions. Under certain hypotheses, these estimates can be shown to lead to upper and lower bounds for the free energy of the composite, which reduce to standard results when the intra-phase fluctuations vanish. An illustrative application is given for rigidly reinforced composites with a non-uniform distribution of the thermal stress in the matrix phase

Explaining the environmentally sustainable consumer behavior: a social capital perspective

Purpose - The purpose of this study is to examine the effects of social capital within a community on the adoption of consumer eco-behaviour or environmentally sustainable behaviour of consumers. The authors draw on the behavioural perspective model (BPM) of consumer behaviour and social capital theory in arguing that social capital shapes a consumer\u27s knowledge of environmental issues and pro-environmental attitudes, which in turn influence a consumer\u27s perceived capability to engage in eco-behaviour. Design/methodology/approach - This study uses partial least squares approach to structural equation modelling of survey data involving 1,044 consumers in the Philippines. It involves testing of a measurement model to examine the validity and reliability of the constructs used in the study. This is followed by testing of the structural models to test the hypothesised relationships of the constructs. Findings - The results suggest the substantive influence of social capital on environmental knowledge, pro-environmental attitudes and eco-capability. Both knowledge and attitudes have positive effects on eco-capability, which in turn positively shapes eco-behaviour. Research limitations/implications - Future studies can examine how social capital as a multi-dimensional construct impacts context-specific consumer behaviour. Practical implications - Social and environmental marketing may focus on social network activation to encourage eco-behaviours of consumers. Social implications - Findings highlight the role of social capital within one\u27s community as a resource channel to encourage environmentally responsible consumer behaviour. Originality/value - The study extends the BPM by offering a social capital view as a more nuanced explanation of consumer eco-behaviour

The Structure and Star-Formation History of NGC 5461

We compute photoionization models for the giant extragalactic H II region NGC 5461, and compare their predictions to several observational constraints. Since we aim at reproducing not only the global properties of the region, but its local structure also, the models are constrained to reproduce the observed density profile, and our analysis takes into consideration the bias introduced by the shapes and sizes of the slits used by different observers. We find that an asymmetric nebula with a gaussian density distribution, powered by a young burst of 3.1 Myr, satisfactorily reproduces most of the constraints, and that the star-formation efficiency inferred from the model agrees with current estimates. Our results strongly depend on the assumed density law, since constant density models overestimate the hardness of the ionizing field, affecting the deduced properties of the central stellar cluster. We illustrate the features of our best model, and discuss the possible sources of errors and uncertainties affecting the outcome of this type of studies.Comment: 33 pages (LaTeX), 3 .eps figures. to be published in ApJ, May 200

Modeling Heterogeneous Materials via Two-Point Correlation Functions: I. Basic Principles

Heterogeneous materials abound in nature and man-made situations. Examples include porous media, biological materials, and composite materials. Diverse and interesting properties exhibited by these materials result from their complex microstructures, which also make it difficult to model the materials. In this first part of a series of two papers, we collect the known necessary conditions on the standard two-point correlation function S2(r) and formulate a new conjecture. In particular, we argue that given a complete two-point correlation function space, S2(r) of any statistically homogeneous material can be expressed through a map on a selected set of bases of the function space. We provide new examples of realizable two-point correlation functions and suggest a set of analytical basis functions. Moreover, we devise an efficient and isotropy- preserving construction algorithm, namely, the Lattice-Point algorithm to generate realizations of materials from their two- point correlation functions based on the Yeong-Torquato technique. Subsequent analysis can be performed on the generated images to obtain desired macroscopic properties. These developments are integrated here into a general scheme that enables one to model and categorize heterogeneous materials via two-point correlation functions.Comment: 37 pages, 26 figure