2,328 research outputs found

    From Foraging to Agriculture

    Get PDF
    We consider a world in which the mode of food production, foraging or agriculture, is endogenous, and in which technology grows exogenously. Using a recent model of coalition formation, we allow individuals to rationally form cooperative communities (bands) of foragers or farmers. At the lowest levels of technology, equilibrium entails the grand coalition of foragers, a cooperative structure which avoids over-exploitation of the environment. But at a critical state of technology, the cooperative structure breaks down through an individually rational splintering of the band. At this stage there can be an increase in work and, through the over-exploitation of the environment, a food crisis. In the end, technological growth leads to a one-way transition from foraging to agriculture.

    Tariff Wars and Trade Deals With Costly Government

    Get PDF
    We study a simple model of tariff wars and trade deals in which government revenue collection and disbursement uses resources. The introduction of a costly government leads to lower non-cooperative tariffs, the possibility that a less costly government may win a tariff war, and fully cooperative trade deals where countries lower tariffs but do not eliminate them, even with lump-sum taxes and transfers.

    Tariff Wars and Trade Deals with Costly Government

    Get PDF
    We study a simple model of tariff wars and trade deals in which government revenue collection and disbursement uses resources. The introduction of costly governments leads to lower non–cooperative tariffs, the possibility that a less costly government may win a tariff war, and fully cooperative trade deals where countries lower tariffs but do not eliminate them, even with lump–sum taxes and transfers.

    Towards a Better System for Immigration Control

    Get PDF
    We study different methods of immigration control using a simple model of a congested world. Our main comparison involves quota, the predominant instrument of immigration control, and a proposed system of immigration tolls and emigration subsidies. We show that the equilibrium of the proposed system is Pareto superior to the quota system. This is consistent with the tolls and subsidies creating a market for international migrants. When countries are price-takers the market becomes perfect and the exploitation of gains from trade complete. From a normative perspective, an open-borders policy is preferred to both control methods but will meet political opposition because it hurts the residents of the rich country.

    Federations, Constitutions, and Political Bargaining

    Get PDF
    The paper studies a world where a region provides essential inputs for the successful implementation of a local public policy project with spill-overs, and where bargaining between different levels of government may ensure efficient decision making ex post. We ask whether the authority over the public policy measure should rest with the local government or be centralized, allowing financial relationships within the federation to be designed optimally. We show that centralization is always dominant when governments are benevolent, and that both governance structures are otherwise inefficient as long as political bargaining is disregarded. With bargaining, however, the first best can often be achieved under decentralization, but not under centralization. At the root of the result is the alignment of decision making over both essential inputs and final project size under decentralization.Federalism, Constitutions, Decentralization, Grants, Political Bargaining.

    In vitro evaluation of the potential role of sulfite radical in morphine-associated histamine release

    Get PDF
    BACKGROUND: Intravenous morphine use is associated with elevated histamine release leading to bronchoconstriction, edema and hemodynamic instability in some patients. This study evaluated the possibility that sulfite, which is present as a preservative in many morphine preparations, might contribute to histamine release in vitro. RESULTS: The human mast cell line, HMC-1, was exposed to various morphine concentrations, in the absence of sulfite, under cell culture conditions. Clinically attained concentrations of morphine (0.018ÎĽg/ml and 0.45ÎĽg/ml) did not cause increased histamine release from mast cells. There was a significant increase in histamine release when the morphine concentration was increased by 1184-fold (668ÎĽg/ml morphine). Histamine release from mast cells exposed to morphine and/or sulfite required the presence of prostaglandin H synthetase. Histamine release in experiments using sulfite-containing morphine solutions was not statistically different from that observed in morphine-only solutions. CONCLUSION: Sulfite in sulfite-containing morphine solutions, at concentrations seen clinically, is not responsible for histamine release in in vitro experiments of the human mast cell line, HMC-1. This does not preclude the fact that sulfite may lead to elevation of histamine levels in vivo

    Infanticide and Human Self Domestication

    Get PDF
    Our hypothesis, which is largely complementary to Wrangham, is that band elders engaged in infanticide and direct and indirect child homicide against the offspring of reactive aggressive adults through decisions during the foraging period of the Middle and Upper Pleistocene. We hypothesize that elders may have targeted the offspring of reactively aggressive males (and females) as retaliation for behaviors that were not good for the elders or their offspring and because surreptitiously killing the offspring of violent males was much less dangerous to the elders than killing the violent males. Such retaliation could have selected against reactive aggression as a genetic consequence. In other words, infanticide could have been Wrangham\u27s “different stimulus” initiating HSD. Our argument is that the earliest language of single words (kill), and certainly the crude compounds, “kill-baby or “like father” and “like son,” would be enough to organize the “execution of an infant” in a relatively secluded birthing site. Infanticide effectively becomes a second moment of mate choice. Such an action could have been relatively safely concealed since an infant dying in childbirth in forager socio-ecological conditions was likely not unusual (see below). The relative simplicity of the language capacities necessary for infanticide contrasts with the more sophisticated language necessary to organize a safe coup and execution of a reactively aggressive alpha male

    GW Librae: Still Hot Eight Years Post-Outburst

    Get PDF
    We report continued Hubble Space Telescope (HST) ultraviolet spectra and ground-based optical photometry and spectroscopy of GW Librae eight years after its largest known dwarf nova outburst in 2007. This represents the longest cooling timescale measured for any dwarf nova. The spectra reveal that the white dwarf still remains about 3000 K hotter than its quiescent value. Both ultraviolet and optical light curves show a short period of 364-373 s, similar to one of the non-radial pulsation periods present for years prior to the outburst, and with a similar large UV/optical amplitude ratio. A large modulation at a period of 2 h (also similar to that observed prior to outburst) is present in the optical data preceding and during the HST observations, but the satellite observation intervals did not cover the peaks of the optical modulation so it is not possible to determine its corresponding UV amplitude. The similarity of the short and long periods to quiescent values implies the pulsating, fast spinning white dwarf in GW Lib may finally be nearing its quiescent configuration.Comment: 6 figures, accepted in A

    Bayesian High-Redshift Quasar Classification from Optical and Mid-IR Photometry

    Get PDF
    We identify 885,503 type 1 quasar candidates to i<22 using the combination of optical and mid-IR photometry. Optical photometry is taken from the Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III/BOSS), while mid-IR photometry comes from a combination of data from the Wide-Field Infrared Survey Explorer (WISE) "ALLWISE" data release and several large-area Spitzer Space Telescope fields. Selection is based on a Bayesian kernel density algorithm with a training sample of 157,701 spectroscopically-confirmed type-1 quasars with both optical and mid-IR data. Of the quasar candidates, 733,713 lack spectroscopic confirmation (and 305,623 are objects that we have not previously classified as photometric quasar candidates). These candidates include 7874 objects targeted as high probability potential quasars with 3.5<z<5 (of which 6779 are new photometric candidates). Our algorithm is more complete to z>3.5 than the traditional mid-IR selection "wedges" and to 2.2<z<3.5 quasars than the SDSS-III/BOSS project. Number counts and luminosity function analysis suggests that the resulting catalog is relatively complete to known quasars and is identifying new high-z quasars at z>3. This catalog paves the way for luminosity-dependent clustering investigations of large numbers of faint, high-redshift quasars and for further machine learning quasar selection using Spitzer and WISE data combined with other large-area optical imaging surveys.Comment: 54 pages, 17 figures; accepted by ApJS Data for tables 1 and 2 available at http://www.physics.drexel.edu/~gtr/outgoing/optirqsos/data/master_quasar_catalogs.011414.fits.bz2 and http://www.physics.drexel.edu/~gtr/outgoing/optirqsos/data/optical_ir_quasar_candidates.052015.fits.bz

    Immigration Control and the Welfare State

    Get PDF
    We examine immigratuon policy and its redistributive effects using a model of a rich country which must spend on border control in order to regulate immigration from a poor country. There are owners and workers in the rich country, and a public sector which makes redistributive transfers from owners to workers. We first consider the case where illegal immigrants have access to the public sector, a situation currently observed in many countries. We show that as border control becomes more expensive inequality in the rich country increases, redistributive transfers may increase or decrease, some immigration is permitted and foreign aid may be used by the rich country in order to reduce the migration pressure along its border with the poor country. Because of nonconvexities, we also show a small decrease in the aversion to collapse of the redistributive public sector. We then consider excluding illegal immigrants from the public sector (eg. Califronia Proposition 187). We find that the possibility of collapse vanishes and that the rich country takes the toughest official stance on migration but does not enforce it with border controls.
    • …
    corecore