Hypothetical Intertemporal Consumption Choices

The paper extends and replicates part of the analysis by Barsky, Juster, Kimball, and Shapiro (1997), which exploits hypothetical choices among different consumption streams to infer intertemporal substitution elasticities and rates of time preference.We use a new and much larger dataset than Barsky et al. Furthermore, we estimate structural models of intertemporal choice, while parameterizing the parameters of interest as a function of relevant individual characteristics.We also consider lobehaviorallc extensions, like habit formation.Models with habit formation appear to be superior to models with intertemporally additive preferences.consumer choice;econometric models

Saving and Habit Formation: Evidence from Dutch Panel Data

This paper focuses on the role of habit formation in individual preferences over consumption and saving.We closely relate to Alessie and Lusardi's (1997) model as we estimate a model which is based on their closed-form solution, where saving is expressed as a function of lagged saving and other regressors. Alternatively, we could use an Euler-equation approach (see e.g.Guariglia and Rossi (2001) and Dynan (2000)), but we will argue that this approach may yield spuriously negative estimates of the habit formation parameter because in surveys consumption is typically measured with considerable error.A second reason to use the closed form solution as a basis of the empirical model is that it embodies more information about the habit formation model than the Euler equation.Therefore, the closed form solution allows for a more powerful test of the validity of the habit formation model than the Euler equation approach.preferences;savings;incomes;habit formation

Subjective Measures of Risk Aversion and Portfolio Choice

risk aversion;portfolio choice;subjective measures;econometric models

Evolution of Vacuum Bubbles Embeded in Inhomogeneous Spacetimes

We study the propagation of bubbles of new vacuum in a radially inhomogeneous background filled with dust or radiation, and including a cosmological constant, as a first step in the analysis of the influence of inhomogeneities in the evolution of an inflating region. We also compare the cases with dust and radiation backgrounds and show that the evolution of the bubble in radiation environments is notably different from that in the corresponding dust cases, both for homogeneous and inhomogeneous ambients, leading to appreciable differences in the evolution of the proper radius of the bubble.Comment: 18 pages, 15 figures, accepted for publication in Journal of Cosmology and Astroparticle Physics (new version with a few cosmetic changes w.r.t. the published one

Structure of Compact Stars in R-squared Palatini Gravity

We analyse configurations of compact stars in the so-called R-squared gravity in the Palatini formalism. Using a realistic equation of state we show that the mass-radius configurations are lighter than their counterparts in General Relativity. We also obtain the internal profiles, which run in strong correlation with the derivatives of the equation of state, leading to regions where the mass parameter decreases with the radial coordinate in a counter-intuitive way. In order to analyse such correlation, we introduce a parametrisation of the equation of state given by multiple polytropes, which allows us to explicitly control its derivatives. We show that, even in a limiting case where hard phase transitions in matter are allowed, the internal profile of the mass parameter still presents strange features and the calculated M-R configurations also yield NSs lighter than those obtained in General Relativity.Comment: 9 pages, 5 figures. Accepted for publication in General Relativity and Gravitatio

Is Information Overrated?:Evidence from the Pension Domain

This paper presents empirical evidence from the Netherlands indicating that the current policy based on information is unlikely to help people make the pension choices required in a system in which employees are the ultimate bearers of asset market risk. This holds even if information is made easier to understand, disseminated by the relevant media, and provided made to measure. The paper offers a behavioral explanation of the findings and concludes that policy makers, financial supervisors, and the pension industry should adopt alternative instruments for helping employees make good choices. These strategies may be useful in the context of recent proposals for a structural change of the pension system, including the increase in the eligibility age for the first layer pension (AOW)

Cosmography and the redshift drift in Palatini f(R)f({\cal R}) theories

We present an application to cosmological models in $f({\cal R})$ theories within the Palatini formalism of a method that combines cosmography and the explicit form of the field equations in the calculation of the redshift drift. The method yields a sequence of constraint equations which lead to limits on the parameter space of a given $f({\cal R})$-model. Two particular families of $f({\cal R})$-cosmologies capable of describing the current dynamics of the universe are explored here: (i) power law theories of the type $f({\cal R})={\cal R}-\beta /{\cal R}^n$, and (ii) theories of the form $f({\cal R})={\cal R}+\alpha \ln{{\cal R}} -\beta$. The constraints on $(n,\beta)$ and $(\alpha,\beta)$, respectively, limit the values to intervals that are narrower than the ones previously obtained. As a byproduct, we show that when applied to General Relativity, the method yields values of the kinematic parameters with much smaller errors that those obtained directly from observations.Comment: 7 pages, 2 figure