Carrot or Stick? Group Selection and the Evolution of Reciprocal Preferences

This paper studies the evolution of both characteristics of reciprocity - the willingness to reward friendly behavior and the willingness to punish hostile behavior. Firstly, preferences for rewarding as well as preferences for punishing can survive evolution provided individuals interact within separated groups. This holds even with randomly formed groups and even when individual preferences are unobservable. Secondly, preferences for rewarding survive only in coexistence with self-interested preferences. But preferences for punishing tend either to vanish or to dominate the population entirely. Finally, the evolution of preferences for rewarding and the evolution of preferences for punishing influence each other decisively. The existence of rewarders enhances the evolutionary success of punishers, but punishers crowd out rewarders

The Obama/Pentagon War Narrative, the Real War and Where Afghan Civilian Deaths Do Matter

This article investigates two related issues: (1) the on-the-ground experience of the fierce US war. in Afghanistan, in contrast to the Pentagon story and the mainstream media; (2) The relentless efforts of Obama and the Pentagon to control the public account of this war. While the real war spread geographically and violence intensified, so did the efforts of the United States. to build a positive reading. The examination of the corpses (of foreign occupation forces and innocent Afghan civilians) reveals a situation of exchange. The elites of the countries of the NATO countries have understood that they have entered a dead end and begin to back down

Ice in the Tropics: the Export of ‘Crystal Blocks of Yankee Coldness’ to India and Brazil

The Boston natural ice trade thrived during 1830-70 based upon Frederic Tudor’s idea of combining two useless products – natural winter ice in New England ponds and sawdust from Maine’s lumber mills. Tudor ice was exported extensively to the tropics from the West Indies to Brazil and the East Indies as well as to southern ports of the United States. In tropical ice ports, imported natural ice was a luxury product, e.g., serving to chill claret wines (Calcutta), champagne (Havana and Manaus), and mint juleps (New Orleans and Savannah) and used in luxury hotels or at banquets. In the temperate United States, natural ice was employed to preserve foods (cold storage) and to cool water (Americans’ peculiar love of ice water). In both temperate and tropical regions natural ice found some use for medicinal purposes (to calm fevers). With the invention of a new technology to manufacture artificial ice as part of the Industrial Revolution, the natural ice export trade dwindled as import substituting industrialization proceeded in the tropics. By the turn of the twentieth century, ice factories had been established in half a dozen Brazilian port cities. All that remained of the once extensive global trade in natural ice was a sailing ship which docked in Rio Janeiro at Christmas time laden with ice and apples from New England

Nineteenth-Century Bahia\u27s Passion for British Salted Cod: From the Seas of Newfoundland to the Portuguese Shops of Salvador\u27s Cidade Baixa, 1822-1914

Dried cod has played a similar role to sugar in the international chain of commerce. It became a major traded commodity between British North America (Newfoundland, Nova Scotia Gaspe) in the nineteenth century. Cheap cod fed the slaves who grew and produced the sugar (and coffee and cotton) which in turn energised the workers of the Industrial Revolution who worked the machines which made the commodities of empire. The machines in factories and their output provided the material basis of Empire. Sugar and cod were important in the cultures of Britain, Newfoundland, the West Indies, West Africa and Brazil. Demand (tastes) and (low) price dictated that salted cod would become a main staple in the West Indies and Brazil even though ample supplies of fresh fish existed locally

Hard and bright gamma-ray emission at the base of the Fermi bubbles

The Fermi bubbles (FBs) are large gamma-ray emitting lobes extending up to $55\deg$ in latitude above and below the Galactic center (GC). Although the FBs were discovered 8 years ago, their origin and the nature of the gamma-ray emission are still unresolved. Understanding the properties of the FBs near the Galactic plane may provide a clue to their origin. Previous analyses of the gamma-ray emission at the base of the FBs, what remains after subtraction of Galactic foregrounds, have shown an increased intensity compared to the FBs at high latitudes, a hard power-law spectrum without evidence of a cutoff up to approximately 1 TeV, and a displacement of the emission to negative longitudes relative to the GC. We analyze 9 years of Fermi Large Area Telescope data in order to study in more detail the gamma-ray emission at the base of the FBs, especially at energies above 10 GeV. We confirm that the gamma-ray emission at the base of the FBs is well described by a simple power law up to 1 TeV energies. The 95% confidence lower limit on the cutoff energy is about 500 GeV. It has larger intensity than the FBs emission at high latitudes and is shifted to the west (negative longitudes) from the GC. If the emission at the base of the FBs is indeed connected to the high-latitude FBs, then the shift of the emission to negative longitudes disfavors models where the FBs are created by the supermassive black hole at the GC. We find that the gamma-ray spectrum can be explained either by gamma rays produced in hadronic interactions or by leptonic inverse Compton scattering. In the hadronic scenario, the emission at the base of the FBs can be explained either by several hundred supernova remnants (SNRs) near the Galactic center or by about 10 SNRs at a distance of ~ 1 kpc. In the leptonic scenario, the necessary number of SNRs is a factor of a few larger than in the hadronic scenario. (abridged)Comment: 24 pages, 18 figures, published in A&

Monitoring, reporting and vrification for national REDD+programmes: two proposals

Different options have been suggested by Parties to the UNFCCC (United Framework Convention on Climate Change) for inclusion in national approaches to REDD and REDD + (reduced deforestation, reduced degradation, enhancement of forest carbon stocks, sustainable management of forest, and conservation of forest carbon stocks). This paper proposes that from the practical and technical points of view of designing action for REDD and REDD + at local and sub-national level, as well as from the point of view of the necessary MRV (monitoring, reporting and verification), these should be grouped into three categories: conservation, which is rewarded on the basis of no changes in forest stock, reduced deforestation, in which lowered rates of forest area loss are rewarded, and positive impacts on carbon stock changes in forests remaining forest, which includes reduced degradation, sustainable management of forest of various kinds, and forest enhancement. Thus we have moved degradation, which conventionally is grouped with deforestation, into the forest management group reported as areas remaining forest land, with which it has, in reality, and particularly as regards MRV, much more in common. Secondly, in the context of the fact that REDD/REDD + is to take the form of a national or near-national approach, we argue that while systematic national monitoring is important, it may not be necessary for REDD/REDD + activities, or for national MRV, to be started at equal levels of intensity all over the country. Rather, areas where interventions seem easiest to start may be targeted, and here data measurements may be more rigorous (Tier 3), for example based on stakeholder self-monitoring with independent verification, while in other, untreated areas, a lower level of monitoring may be pursued, at least in the first instance. Treated areas may be targeted for any of the three groups of activities (conservation, reduced deforestation, and positive impact on carbon stock increases in forest remaining forest)

Portfolio choice and estimation risk : a comparison of Bayesian approaches to resampled efficiency

Estimation risk is known to have a huge impact on mean/variance (MV) optimized portfolios, which is one of the primary reasons to make standard Markowitz optimization unfeasible in practice. Several approaches to incorporate estimation risk into portfolio selection are suggested in the earlier literature. These papers regularly discuss heuristic approaches (e.g., placing restrictions on portfolio weights) and Bayesian estimators. Among the Bayesian class of estimators, we will focus in this paper on the Bayes/Stein estimator developed by Jorion (1985, 1986), which is probably the most popular estimator. We will show that optimal portfolios based on the Bayes/Stein estimator correspond to portfolios on the original mean-variance efficient frontier with a higher risk aversion. We quantify this increase in risk aversion. Furthermore, we review a relatively new approach introduced by Michaud (1998), resampling efficiency. Michaud argues that the limitations of MV efficiency in practice generally derive from a lack of statistical understanding of MV optimization. He advocates a statistical view of MV optimization that leads to new procedures that can reduce estimation risk. Resampling efficiency has been contrasted to standard Markowitz portfolios until now, but not to other approaches which explicitly incorporate estimation risk. This paper attempts to fill this gap. Optimal portfolios based on the Bayes/Stein estimator and resampling efficiency are compared in an empirical out-of-sample study in terms of their Sharpe ratio and in terms of stochastic dominance