Modelling Charitable Donations to an Unexpected Natural Disaster: Evidence from the U.S. Panel Study of Income Dynamics

Using household-level data, we explore the relationship between donations to the victims of the 2004 Indian Ocean tsunami disaster and other charitable donations. The empirical evidence suggests that donations specifically for the victims of the tsunami are positively associated with the amount previously donated to other charitable causes, which accords with complementary rather than substitution effects. This relationship exists when we decompose overall charitable donations into different types of philanthropy, with charitable contributions to caring, needy and religious organizations having the largest positive association with donations to the victims of the tsunami. When we explore the impact of donations to the victims of the tsunami on future donations to charity, however, our findings suggest an inverse relationship with the largest inverse association with donations to needy and caring organizations

Modelling charitable donations: A latent class panel approach

We apply a latent class tobit framework to the analysis of charitable donations at the household level where the latent class aspect of the model splits households into two groups, which we subsequently interpret as "low" donators and "high" donators. Then the tobit part of the model explores the determinants of the amount donated by each household conditional on being in that class. We consider both total donations and also separately religious donations. Our findings, which are based on US panel data, suggest that price and labour income elasticities differ substantially across the two classes. The inverse price effect is most pronounced for the "low" donators group for both total and religious donations. The labour income elasticity switches direction of influence upon charitable donations across the two latent classes with a negative influence for the "high" donators group and a positive influence for the "low" donators group, for the case of total donations to charity, a pattern which is reversed in the case of solely religious donations

Modelling Charitable Donations to an Unexpected Natural Disaster: Evidence from the U.S. Panel Study of Income Dynamics

Using household-level data, we explore the relationship between donations to the victims of the 2004 Indian Ocean tsunami disaster and other charitable donations. The empirical evidence suggests that donations specifically for the victims of the tsunami are positively associated with the amount previously donated to other charitable causes, which accords with complementary rather than substitution effects. This relationship exists when we decompose overall charitable donations into different types of philanthropy, with charitable contributions to caring, needy and religious organizations having the largest positive association with donations to the victims of the tsunami. When we explore the impact of donations to the victims of the tsunami on future donations to charity, however, our findings suggest an inverse relationship with the largest inverse association with donations to needy and caring organizations

Modelling primary health care use: a panel zero inflated interval regression approach

We introduce the (panel) zero-inflated interval regression (ZIIR) model, to investigate GP visits using individual-level data from the British Household Panel Survey. The ZIIR is particularly suitable for this application as it jointly estimates the probability of visiting the GP and then, conditional on visiting, the frequency of visits (defined by given numerical intervals in the data). The results show that different socio-economic factors influence the probability of visiting the GP and the frequency of visits

Financial expectations and household consumption : does middle inflation matter?

Using British panel data, we explore the Finding that households often expect their financial position to remain unchanged compared to other alternatives, using a generalised middle inflated ordered probit (GMIOP) model. In doing so we account for the tendency of individuals to choose ‘neutral’ responses when faced with attitudinal and opinion-based questions, which are a common feature of survey data. Our empirical analysis strongly supports the use of a GMIOP model to account for this response pattern. Expectations indices based on competing discrete choice models are then exploited to explore the role that financial expectations play in driving the consumption of different types of durable goods and the amount of expenditure undertaken. Whilst financial optimism is significantly associated with consumption, indices which fail to take into account middle-inflation are found to overestimate the impact of financial expectations

Modelling the composition of household portfolios: a latent class approach

We introduce the latent class modelling approach to the analysis of financial portfolio diversification at the household level. We explore portfolio allocation in Great Britain using household panel data based on a nationally representative sample of the population, namely the Wealth and Assets Survey. The latent class aspect of the model splits households into four groups, which serves to unveil a more detailed picture of the determinants of portfolio diversification than existing econometric approaches. Our findings reveal a pattern of class heterogeneity that conventional econometric models are unable to identify as the statistical significance as well as the direction of the effect of some explanatory variables varies across the four classes. When comparing our preferred latent class estimator to the commonly used approaches, we find that treating the population as a single homogeneous group may lead to biased parameter estimates and suggests that policy based on such models could be inappropriate or erroneous

Mental Health and Reporting Bias: Analysis of the GHQ - 12

Measures of mental wellbeing are heavily relied upon to identify at-risk individuals. However, self-reported mental health metrics might be unduly affected by mis-reporting (perhaps stemming from stigma effects). In this paper we consider this phenomenon using data from the British Household Panel Survey (BHPS) and its successor, Understanding Society, the UK Household Longitudinal Study (UKHLS) over the period 1991 to 2016. In particular, in separate analyses of males and females we focus on the GHQ-12 measure, and specifically its sub-components, and how inaccurate reporting can adversely affect the distribution of the index. The results suggest that individuals typically over-report pyschological wellbeing and that reporting bias is greater for males. The results are then used to adjust the composite GHQ- 12 score to take such mis-reporting behaviours into account. To further illustrate the importance of this, we compare the effects of the adjusted and unadjusted GHQ-12 index when modelling a number of economic transitions. The results reveal that using the original GHQ-12 score generally leads to an underestimate of the effect of psychological distress on transitions into improved economic states, such as unemployment into employment

Reversible Pressure-Induced Amorphization in Solid C70 : Raman and Photoluminescence Study

We have studied single crystals of $C_{70}$ by Raman scattering and photoluminescence in the pressure range from 0 to 31.1 GPa. The Raman spectrum at 31.1 GPa shows only a broad band similar to that of the amorphous carbon without any trace of the Raman lines of $C_{70}$. After releasing the pressure from 31.1 GPa, the Raman and the photoluminescence spectra of the recovered sample are that of the starting $C_{70}$ crystal. These results indicate that the $C_{70}$ molecules are stable upto 31.1 GPa and the amorphous carbon high pressure phase is reversible, in sharp contrast to the results on solid $C_{60}$. A qualitative explaination is suggested in terms of inter- versus intra-molecular interactions.Comment: To appear in Phys. Rev. Lett., 12 pages, RevTeX (preprint format), 3 figures available upon reques

An observation of spin-valve effects in a semiconductor field effect transistor: a novel spintronic device

We present the first spintronic semiconductor field effect transistor. The injector and collector contacts of this device were made from magnetic permalloy thin films with different coercive fields so that they could be magnetized either parallel or antiparallel to each other in different applied magnetic fields. The conducting medium was a two dimensional electron gas (2DEG) formed in an AlSb/InAs quantum well. Data from this device suggest that its resistance is controlled by two different types of spin-valve effect: the first occurring at the ferromagnet-2DEG interfaces; and the second occuring in direct propagation between contacts.Comment: 4 pages, 2 figure