Do Imports and Exports Adjust Nonlinearly? Evidence from 100 Countries

A country is said to live within its international budget constraint if its exports and imports are cointegrated. Previous studies that tried to verify the cointegration between exports and imports used linear models and supported the theory in almost 50% of countries. In this paper, when we use the nonlinear ARDL approach and asymmetry cointegration method, we support the long-run link between imports and exports in 94 out of 100 countries in our sample. This study is not only the most comprehensive study in the literature, but it is also the first to show that, indeed, trade flows adjust in a nonlinear fashion

The Leptonic Higgs as a Messenger of Dark Matter

We propose that the leptonic cosmic ray signals seen by PAMELA and ATIC result from the annihilation or decay of dark matter particles via states of a leptonic Higgs doublet to $\tau$ leptons, linking cosmic ray signals of dark matter to LHC signals of the Higgs sector. The states of the leptonic Higgs doublet are lighter than about 200 GeV, yielding large $\bar{\tau} \tau$ and $\bar{\tau} \tau \bar{\tau} \tau$ event rates at the LHC. Simple models are given for the dark matter particle and its interactions with the leptonic Higgs, for cosmic ray signals arising from both annihilations and decays in the galactic halo. For the case of annihilations, cosmic photon and neutrino signals are on the verge of discovery.Comment: 34 pages, 9 figures, minor typos corrected, references adde

Government Spending Cycles: Ideological or Opportunistic?

ands. The time series analysis, covering the period 1953–1993, allows for different types of government spending. In general, spending is inspired by ideological and opportunistic motives: all government expenditure categories show an upward drift during election times and the partisan motives behind government spending are clearly revealed: left-wing cabinets attach greater importance to social security and health care than right-wing cabinets and right-wing cabinets value expenditure on infrastructure and defense more than left-wing parties. Constructive comments by Frans van Winden, Wilko Letterie, Peter Cornelisse, Arie Ros, André de Moor, Harry ter Rele and an anonymous referee are gratefully acknowledged

Supersymmetric Dark Matter and Yukawa Unification

An analysis of supersymmetric dark matter under the Yukawa unification constraint is given. The analysis utilizes the recently discovered region of the parameter space of models with gaugino mass nonuniversalities where large negative supersymmetric corrections to the b quark mass appear to allow $b-\tau$ unification for a positive $\mu$ sign consistent with the $b\to s+\gamma$ and $g_{\mu}-2$ constraints. In the present analysis we use the revised theoretical determination of $a_{\mu}^{SM}$ ($a_{\mu}= (g_{\mu}-2)/2$) in computing the difference $a_{\mu}^{exp}-a_{\mu}^{SM}$ which takes account of a reevaluation of the light by light contribution which has a positive sign. The analysis shows that the region of the parameter space with nonuniversalities of the gaugino masses which allows for unification of Yukawa couplings also contains regions which allow satisfaction of the relic density constraint. Specifically we find that the lightest neutralino mass consistent with the relic density constraint, $b\tau$ unification for SU(5) and $b-t-\tau$ unification for SO(10) in addition to other constraints lies in the region below 80 GeV. An analysis of the maximum and the minimum neutralino-proton scalar cross section for the allowed parameter space including the effect of a new determination of the pion-nucleon sigma term is also given. It is found that the full parameter space for this class of models can be explored in the next generation of proposed dark matter detectors.Comment: 28 pages,nLatex including 5 fig

Industry concentration and strategic trade policy in successive oligopoly

We study a policy game between exporting and importing countries in vertically linked industries. In a successive international Cournot oligopoly, we analyse incentives for using tax instruments strategically to shift rents vertically, between exporting and importing countries, and horizontally, between exporting countries. We show that the equilibrium outcome depends crucially on the relative degree of competitiveness in the upstream and downstream parts of the industry. With respect to national welfare, a more competitive upstream industry may benefit an exporting (upstream) country and harm an importing (downstream) country. On the other hand, a more competitive downstream industry may harm exporting countries.Financial support from the Norwegian Research Council, through the PETROPOL research programme, is gratefully acknowledged. The paper has been greatly improved by the suggestions of two anonymous referees. We also thank Hisashi Hokari and Frode Meland for valuable comments and suggestions

Asymmetric Regulation of Identical Polluters in Oligopoly Models

Studies of optimal second-best environmental regulation of identical polluting agents have invariably ignored potentially welfare-improving asymmetric regulation by imposing equal regulatory treatment of identical firms at the outset. Yet, cost asymmetry between oligopoly firms may well give rise to private as well as social gains. A trade-off is demonstrated for the regulator, between private costs savings and additional social costs when asymmetric treatment is allowed. Asymmetry is indeed optimal for a range of plausible parameter values. Further, it is demonstrated that for a broad class of abatement cost functions, there is scope for increasing welfare while keeping both total output and total emission constant. Some motivating policy issues are discussed in light of the results, including international harmonization and global carbon dioxide reduction. Copyright Springer 2005asymmetric emissions regulation, polluting oligopolists, EU harmonization,