Of the Stability of Partnerships When Individuals Have Outside Options, or Why Allowing Exit is Inefficient

Should people be allowed to leave joint projects freely or should they be deterred from breaking off? This depends on why people stop collaborating and whether they have good reasons to do so. We explore the factors that lead to the breakdown of partnerships by studying a public good game with imperfect public monitoring and an exit option. In our experiment, subjects were assigned a partner with whom they could contribute over several periods to a public good with stochastic out- comes. They could choose in each period between participating in the public project or working on their own. We find there was excessive exit especially because subjects over-estimated the likelihood their partner would leave. Treatments with high barriers to exit generated higher welfare overall as they fostered stability and prevented inefficient breakdowns in relationships. There were differences across treatments in the intensity with which different factors drove the choice to work alone. Differences in expected payoffs between independent and group work were more important as a driver of exit in treatments with low barriers to exit. The intensity of other factors was more constant across treatments, including whether the common project failed in the previous period, the belief that one´s partner did not want to maintain the partnership and the belief that he exerted less effort than oneself

Implications of the Quark Mass Hierarchy on Flavor Mixings

We stress that the observed pattern of flavor mixings can be partly interpreted by the quark mass hierarchy without the assumption of specific quark mass matrices. The quantitatively proper relations between the Kobayashi-Maskawa matrix elements and quark mass ratios, such as $$|V_{cb}| \approx |V_{ts}| \approx \sqrt{2} (\frac{m_s}{m_b} -\frac{m_c}{m_t}) [1 + 3 (\frac{m_s}{m_b} + \frac{m_c}{m_t} ) ],$$ are obtainable from a simple {\it Ansatz} of flavor permutation symmetry breaking at the weak scale. We prescribe the same {\it Ansatz} at the supersymmetric grand unified theory scale, and find that its all low-energy consequences on flavor mixings and $CP$ violation are in good agreement with current experimental data.Comment: Latex 19 pages including 5 PS figure

A Natural Supersymmetric Model with MeV Dark Matter

It has previously been proposed that annihilating dark matter particles with MeV-scale masses could be responsible for the flux of 511 keV photons observed from the region of the Galactic Bulge. The conventional wisdom, however, is that it is very challenging to construct a viable particle physics model containing MeV dark matter. In this letter, we challenge this conclusion by describing a simple and natural supersymmetric model in which the lightest supersymmetric particle naturally has a MeV-scale mass and the other phenomenological properties required to generate the 511 keV emission. In particular, the small ($\sim$ $10^{-5}$) effective couplings between dark matter and the Standard Model fermions required in this scenario naturally lead to radiative corrections that generate MeV-scale masses for both the dark matter candidate and the mediator particle.Comment: 4 pages, 1 figure. v2: Small modification to discussion of spectru

Looking in the mirror: Reflecting on 25 years of Inclusive Education in Australia

This is the author accepted manuscript. The final version is available from Taylor & Francis (Routledge) via the DOI in this record.Australia was an early signatory to the Salamanca Statement, and it espouses inclusive education (IE) as the overarching philosophy of education for all. A 2015 critique of IE in Australia (Anderson and Boyle 2015) found that while some gains had been made, particularly in the recognition of the needs of some of the nation’s minority groups, the lack of a nationally accepted understanding of IE meant that it was transpiring in fundamentally distinctive ways across the eight education jurisdictions, with different outcomes for different groups of students. This paper reflects upon why Australia has struggled to enact the recommendations outlined in the Salamanca Statement a quarter of a century ago. The impacts of current education reforms, including the current model of educational provision, the understanding of disability and educational need, and the neo-liberal concepts of standardisation, measurement, and choice are explored. It challenges the idea that IE is the work of schools, and instead argues the need for a national approach to IE. Governments must acknowledge the barriers that their current policies and structures erect and shift towards a more inclusive model of educational delivery – for the benefit of all children and young people in Australia

Steering without navigation equipment: the lamentable state of Australian health policy reform

Steering without navigation equipment This paper comments on some issues of particular concern to Australian health policy makers and some areas needing urgent reform. The two sets of issues do not overlap. It is suggested that there are two fundamental reasons for this. The first is the failure to develop governance structures which promote the identification and resolution of problems according to their importance. The second and related failure is the failure to equip the health services industry with satisfactory navigation equipment – independent research capacity, independent reporting and evaluation – on a scale commensurate with the needs of the country’s largest industry. These two failures together deprive the health system – as a system – of the chief driver of progress in every successful industry in the 20th Century. Concluding comment is made on the National Health and Hospitals Reform Commission which, to date, appears to be following the tradition of ad hoc ‘dab ’ reform aimed, apparently, at one-off improvement rather than the creation of an adaptive, self correcting system, proactively seeking system improvement. The proposals fail to make error learning a central part of ongoing reform