What Can Happiness Research Tell Us about Altruism?: Evidence from the German Socio-Economic Panel

Much progress has been made in recent years on developing and applying a direct measure of utility using survey questions on subjective well-being. In this paper we explore whether this new type of measurement can be fruitfully applied to the study of interdependent utility in general, and altruism between parents and children in particular. We introduce an appropriate econometric methodology and, using data from the German Socio-Economic Panel for the years 2000 - 2002, find that the parents' self-reported happiness depends positively, albeit not very strongly, on the happiness of adult children who moved out.Utility function; Extended family; Fixed effects; Ordered probit

What can happiness research tell us about altruism? Evidence from the German Socio-Economic Panel

Much progress has been made in recent years on developing and applying a direct measure of utility using survey questions on subjective well-being. In this paper we explore whether this new type of measurement can be fruitfully applied to the study of interdependent utility in general, and altruism between parents and adult children who moved away from home in particular. We introduce an appropriate econometric methodology and, using data from the German SocioEconomic Panel for the years 2000-2004, find that the parents’ self-reported happiness depends positively on the happiness of their adult children. A one standard deviation move in the child’s happiness has the same effect as a 45 percent move in household income.utility interdependence, sympathy, extended family, fixed effects

Graphical Modeling for Multivariate Hawkes Processes with Nonparametric Link Functions

Hawkes (1971) introduced a powerful multivariate point process model of mutually exciting processes to explain causal structure in data. In this paper it is shown that the Granger causality structure of such processes is fully encoded in the corresponding link functions of the model. A new nonparametric estimator of the link functions based on a time-discretized version of the point process is introduced by using an infinite order autoregression. Consistency of the new estimator is derived. The estimator is applied to simulated data and to neural spike train data from the spinal dorsal horn of a rat.Comment: 20 pages, 4 figure

Accelerating Monte Carlo simulations with an NVIDIA® graphics processor

Modern graphics cards, commonly used in desktop computers, have evolved beyond a simple interface between processor and display to incorporate sophisticated calculation engines that can be applied to general purpose computing. The Monte Carlo algorithm for modelling photon transport in turbid media has been implemented on an NVIDIA® 8800gt graphics card using the CUDA toolkit. The Monte Carlo method relies on following the trajectory of millions of photons through the sample, often taking hours or days to complete. The graphics-processor implementation, processing roughly 110 million scattering events per second, was found to run more than 70 times faster than a similar, single-threaded implementation on a 2.67 GHz desktop computer

Influence of polarizability on metal oxide properties studied by molecular dynamics simulations

We have studied the dependence of metal oxide properties in molecular dynamics (MD) simulations on the polarizability of oxygen ions. We present studies of both liquid and crystalline structures of silica (SiO2), magnesia (MgO) and alumina (Al2O3). For each of the three oxides, two separately optimized sets of force fields were used: (i) Long-range Coulomb interactions between oxide and metal ions combined with a short-range pair potential. (ii) Extension of force field (i) by adding polarizability to the oxygen ions. We show that while an effective potential of type (i) without polarizable oxygen ions can describe radial distributions and lattice constants reasonably well, potentials of type (ii) are required to obtain correct values for bond angles and the equation of state. The importance of polarizability for metal oxide properties decreases with increasing temperature.Comment: 8 pages, 7 figure

Adaptive optics for laser processing

The overall aim of the work presented in this thesis is to develop an adaptive optics (AO) technique for application to laser-based manufacturing processes. The Gaussian beam shape typically coming from a laser is not always ideal for laser machining. Wavefront modulators, such as deformable mirrors (DM) and liquid crystal spatial light modulators (SLM), enable the generation of a variety of beam shapes and furthermore offer the ability to alter the beam shape during the actual process. The benefits of modifying the Gaussian beam shape by means of a deformable mirror towards a square flat top profile for nanosecond laser marking and towards a ring shape intensity distribution for millisecond laser drilling are presented. Limitations of the beam shaping capabilities of DM are discussed. The application of a spatial light modulator to nanosecond laser micromachining is demonstrated for the first time. Heat sinking is introduced to increase the power handling capabilities. Controllable complex beam shapes can be generated with sufficient intensity for direct laser marking. Conventional SLM devices suffer from flickering and hence a process synchronisation is introduced to compensate for its impact on the laser machining result. For alternative SLM devices this novel technique can be beneficial when fast changes of the beam shape during the laser machining are required. The dynamic nature of SLMs is utilised to improve the marking quality by reducing the inherent speckle distribution of the generated beam shape. In addition, adaptive feedback on the intensity distribution can further improve the quality of the laser machining. In general, beam shaping by means of AO devices enables an increased flexibility and an improved process control, and thus has a significant potential to be used in laser materials processing

Average-case intractability vs. worst-case intractability

AbstractWe show that not all sets in NP (or other levels of the polynomial-time hierarchy) have efficient average-case algorithms unless the Arthur-Merlin classes MA and AM can be derandomized to NP and various subclasses of P/poly collapse to P. Furthermore, other complexity classes like P(PP) and PSPACE are shown to be intractable on average unless they are easy in the worst case

Happiness and altruism within the extended family

We propose a direct measure of altruism between parents and adult children, using survey data on happiness from the German Socio-Economic Panel for the years 2000-2004. The question of altruism within families has policy relevance, for example, to understand whether public transfers crowd out private ones. Previous empirical evidence, based on observed transfer behavior, has failed to establish a clear consensus. Using various cross section, panel data, and instrumental variable estimators, we find a robust association between the happiness of parents and that of their adult children. A 1 standard deviation increase in a child's happiness is associated with the same increase in own happiness as that of a 20-45% increase in household income, depending on specificatio