Applying cognitive perspectives on decision-making to the policy advice process: a practitioner's view

Behavioural economics and the related fields of cognitive and social psychology are now very much in the mainstream, as the highly visible success of the Behavioural Insights Unit in the United Kingdom attests. A robust and diverse range of findings about the limits of human thinking challenges policy practitioners to reconsider how they both design and advise on policies. This challenge is particularly relevant given that the training and background of policy advisors typically does not include these fields, with political science, law and conventional economics much more common. A range of recent books have popularised many concepts from these fields and are leading an increasing number of people outside academia to revisit the way we conceive of thinking and decision-making. For example, The Wisdom of Crowds (Surowiecki, 2004), Blink (Gladwell, 2005), The Black Swan (Taleb, 2007), Predictably Irrational (Ariely, 2008), Nudge (Thaler and Sunstein, 2008), Thinking Fast and Slow (Kahneman, 2011) and The Signal and the Noise (Silver, 2012) all underline the limitations of rational accounts of thinking and decision-making. Perhaps reflecting the new public popularity of these fields, it has become fashionable in certain circles to consider ways to incorporate the findings of cognitive psychology and behavioural economics into the design of policies (e.g. Ministry of Economic Development, 2006; Dolan et al., 2010), often under the label libertarian paternalism or choice architecture (Thaler, Sunstein and Balz, 2010). The argument is often that small changes in the design of policies can nudge choices in a desired direction without the need for compulsion. Perhaps the best known example is the design of KiwiSaver, where the default option is automatic enrolment, with people required to opt out instead of opt in. • Tim Hughes studied economics at the University of Auckland and has worked in policy roles at the Department of Corrections and the Ministry of Social Development. He is currently working in the sector investment team at the Ministry of Justice

The production of matter from curvature in a particular linearized high order theory of gravity and the longitudinal response function of interferometers

The strict analogy between scalar-tensor theories of gravity and high order gravity is well known in literature. In this paper it is shown that, from a particular high order gravity theory known in literature, it is possible to produce, in the linearized approch, particles which can be seen like massive scalar modes of gravitational waves and the response of interferometers to this type of particles is analyzed. The presence of the mass generates a longitudinal force in addition of the transverse one which is proper of the massless gravitational waves and the response of an arm of an interferometer to this longitudinal effect in the frame of a local observer is computed. This longitudinal response function is directly connected with the function of the Ricci scalar in the particular action of this high order theory. Important conseguences from a theoretical point of view could arise from this approach, because it opens to the possibility of using the signals seen from interferometers to understand which is the correct theory of gravitation.Comment: Accepted for Journal of Cosmology and Astroparticle Physic

General indifference pricing with small transaction costs

We study the utility indifference price of a European option in the context of small transaction costs. Considering the general setup allowing consumption and a general utility function at final time T, we obtain an asymptotic expansion of the utility indifference price as a function of the asymptotic expansions of the utility maximization problems with and without the European contingent claim. We use the tools developed in [54] and [48] based on homogenization and viscosity solutions to characterize these expansions. Finally we study more precisely the example of exponential utilities, in particular recovering under weaker assumptions the results of [6].Comment: 43 page

Gravitational Waves Astronomy: a cornerstone for gravitational theories

Realizing a gravitational wave (GW) astronomy in next years is a great challenge for the scientific community. By giving a significant amount of new information, GWs will be a cornerstone for a better understanding of gravitational physics. In this paper we re-discuss that the GW astronomy will permit to solve a captivating issue of gravitation. In fact, it will be the definitive test for Einstein's general relativity (GR), or, alternatively, a strong endorsement for extended theories of gravity (ETG).Comment: To appear in Proceedings of the Workshop "Cosmology, the Quantum Vacuum and Zeta Functions" for the celebration of Emilio Elizalde's sixtieth birthday, Barcelona, March 8-10, 201

The orbital evolution of asteroids, pebbles and planets from giant branch stellar radiation and winds

The discovery of over 50 planets around evolved stars and more than 35 debris discs orbiting white dwarfs highlight the increasing need to understand small body evolution around both early and asymptotic giant branch (GB) stars. Pebbles and asteroids are susceptible to strong accelerations from the intense luminosity and winds of GB stars. Here, we establish equations that can model time-varying GB stellar radiation, wind drag and mass loss. We derive the complete three-dimensional equations of motion in orbital elements due to (1) the Epstein and Stokes regimes of stellar wind drag, (2) Poynting-Robertson drag, and (3) the Yarkovsky drift with seasonal and diurnal components. We prove through averaging that the potential secular eccentricity and inclination excitation due to Yarkovsky drift can exceed that from Poynting-Robertson drag and radiation pressure by at least three orders of magnitude, possibly flinging asteroids which survive YORP spin-up into a widely dispersed cloud around the resulting white dwarf. The GB Yarkovsky effect alone may change an asteroid's orbital eccentricity by ten per cent in just one Myr. Damping perturbations from stellar wind drag can be just as extreme, but are strongly dependent on the highly uncertain local gas density and mean free path length. We conclude that GB radiative and wind effects must be considered when modelling the post-main-sequence evolution of bodies smaller than about 1000 km.Comment: Corrected Fig. 3 and Eq. 14 (In Press, MNRAS

Reflection and Ducting of Gravity Waves Inside the Sun

Internal gravity waves excited by overshoot at the bottom of the convection zone can be influenced by rotation and by the strong toroidal magnetic field that is likely to be present in the solar tachocline. Using a simple Cartesian model, we show how waves with a vertical component of propagation can be reflected when traveling through a layer containing a horizontal magnetic field with a strength that varies with depth. This interaction can prevent a portion of the downward-traveling wave energy flux from reaching the deep solar interior. If a highly reflecting magnetized layer is located some distance below the convection zone base, a duct or wave guide can be set up, wherein vertical propagation is restricted by successive reflections at the upper and lower boundaries. The presence of both upward- and downward-traveling disturbances inside the duct leads to the existence of a set of horizontally propagating modes that have significantly enhanced amplitudes. We point out that the helical structure of these waves makes them capable of generating an alpha-effect, and briefly consider the possibility that propagation in a shear of sufficient strength could lead to instability, the result of wave growth due to over-reflection.Comment: 23 pages, 5 figures. Accepted for publication in Solar Physic