Did the Hilda collisional family form during the late heavy bombardment?

We model the long-term evolution of the Hilda collisional family located in the 3/2 mean-motion resonance with Jupiter. Its eccentricity distribution evolves mostly due to the Yarkovsky/YORP effect and assuming that: (i) impact disruption was isotropic, and (ii) albedo distribution of small asteroids is the same as for large ones, we can estimate the age of the Hilda family to be $4_{-1}^{+0}\,{\rm Gyr}$. We also calculate collisional activity in the J3/2 region. Our results indicate that current collisional rates are very low for a 200\,km parent body such that the number of expected events over Gyrs is much smaller than one. The large age and the low probability of the collisional disruption lead us to the conclusion that the Hilda family might have been created during the Late Heavy Bombardment when the collisions were much more frequent. The Hilda family may thus serve as a test of orbital behavior of planets during the LHB. We tested the influence of the giant-planet migration on the distribution of the family members. The scenarios that are consistent with the observed Hilda family are those with fast migration time scales $\simeq 0.3\,{\rm Myr}$ to $3\,{\rm Myr}$, because longer time scales produce a family that is depleted and too much spread in eccentricity. Moreover, there is an indication that Jupiter and Saturn were no longer in a compact configuration (with period ratio $P_{\rm S}/P_{\rm J} > 2.09$) at the time when the Hilda family was created

Intergenerational transfer of time and risk preferences

Date of Acceptance: 03/06/15 Acknowledgements The Chief Scientist Office of the Scottish Government Health and Social Care Directorates funds HERU. The views expressed in this paper are those of the authors only and not those of the funding body. HB received financial support from the Medical Research Council/Economic and Social Research Council/National Institute of Health Research under grant G0802291. This paper uses unit record data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey. The HILDA Project was initiated and is funded by the Australian Government Department of Families, Housing, Community Services and Indigenous Affairs (FaHCSIA) and is managed by the Melbourne Institute of Applied Economic and Social Research (Melbourne Institute). The findings and views reported in this paper, however, are those of the author and should not be attributed to either FaHCSIA or the Melbourne Institute.Peer reviewedPublisher PD

The effect of chronic pain on life satisfaction : evidence from Australian data

Acknowledgements We thank the participants of the 2014 Health Economics Study Group in Sheffield for their useful comments and suggestions. We are grateful to Dr. Agne Suziedelyte and Professor Denzil Fiebig for useful discussions on the methodology of the paper. Special thanks to two anonymous referees and Editor Joanna Coast for valuable comments and suggestions. This paper uses unit record data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey. The HILDA Project was initiated and is funded by the Australian Government Department of Social Services (DSS) and is managed by the Melbourne Institute of Applied Economic and Social Research (Melbourne Institute). The findings and views reported in this paper, however, are those of the authors and should not be attributed to either DSS or the Melbourne Institute. The Health Economics Research Unit is supported in part by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates.Peer reviewedPostprin

Earning Motivation and The Conventional Earning Function

People have different motivation for having a paid job, and this might came from different expectation, value and also gender roles. Nevertheless, most analysis of earning determinant has neglected this possibility. Using data from Household, Income and Labour Dynamics (HILDA) in Australia in 2001 and 2004, this paper investigates the structure of human capital earning equation and its stability after controlling for earning motivation. The results suggest that some measure of earning motivation have effects. However, even after controlling for earning motivation, the returns to schooling and experience do not change significantly. This suggests that the conventional earning function is stable and robust with respect to the influences of earning motivation.return to education, earning motivation, wage, HILDA

Visible and infrared investigations of planet-crossing asteroids and outer solar system objects

The project is supporting lightcurve photometry, colorimetry, thermal radiometry, and astrometry of selected asteroids. Targets include the planet-crossing population, particularly Earth approachers, which are believed to be the immediate source of terrestrial meteorites, future spacecraft targets, and those objects in the outer belt, primarily the Hilda and Trojan populations, that are dynamically isolated from the main asteroid belt. Goals include the determination of population statistics for the planet-crossing objects, the characterization of spacecraft targets to assist in encounter planning and subsequent interpretation of the data, a comparison of the collisional evolution of dynamically isolated Hilda and Trojan populations with the main belt, and the determination of the mechanism driving the activity of the distant object 2060 Chiron

Reforming Youth Allowance: The “Independent-at- Home” Category

Several of the Youth Allowance eligibility criteria for independent status were subject to severe criticism in the recent Review of Australian Higher Education (2008). Specifically, it seems to be the case that many students are able to qualify for socalled “independent-at-home” financial support even though they may be living in circumstances of relative economic advantage. The paper examines the policy and statistical basis for these claims with the use of data from the HILDA survey and reports apparently strong support for the notion that the rules result in important inequities; the evidence was important to the deliberations of the Review Committee. The Commonwealth Government has recently announced changes to YA consistent with these findings.Youth Allowance; student income support; grants; “independent-athome”’ HILDA.

Rotational Properties of Hilda Asteroids Observed by the K2 Mission

Hilda asteroids orbit at the outer edge, or just outside of the Main Belt, occupying the 2:3 mean motion resonance with Jupiter. It is known that the group shows a mixed taxonomy that suggests the mixed origin of Hilda members, having migrated to the current orbit both from the outer Main Belt and from the Trojans swarms. But there are still few observations for comparative studies that help in understanding the Hilda group in deeper details. We identified 125 individual light curves of Hilda asteroids observed by the K2 mission. We found that despite of the mixed taxonomies, the Hilda group highly resembles to the Trojans in the distribution of rotation periods and amplitudes, and even the LR group (mostly C and X-type) Hildas follow this rule. Contrary to the Main Belt, Hilda group lacks the very fast rotators. The ratio of extremely slow rotators (P>100 h) is a surprising 18%, which is unique in the Solar System. The occurrence rate of asteroids with multiple periods (4%) and asteroids with three maxima in the light curves (5%) can be signs of high rate of binarity, which we can estimate as 25% within the Hilda group