Economic determinants of global mobile telephony growth

This study examines the substitution effect between fixed-line and mobile telephony while controlling for the consumption externality associated with telephone networks. A dynamic demand model is estimated using a global telecommunications panel dataset comprised of 56 countries from 1995–2000. Estimation results show the presence of a substantial substitution effect. Additionally income and own-price elasticities are reported. Analysis of impulse responses for price, income and network size indicate substantial mobile telephone growth is yet to be realised. However, price ceilings imposed in the fixed-line network can retard the growth of the mobile network.

New Matter Effects and BBN Constraints for Mass Varying Neutrinos

The presence of light (m_a ~ 10^-6 ev) scalar fields in the early universe can modify the cosmology of neutrinos considerably by allowing their masses to vary on cosmological times. In this paper, we consider the effect of Planck-suppressed couplings of this scalar to electrons and show that such couplings can easily make new sterile states thermally inaccessible in the early universe, preserving the successes of big bang nucleosynthesis predictions. We consider the circumstances under which these effects give the proper initial conditions for recently considered models of neutrino dark energy, and consider limits from tests of the equivalence principle. The parameters which satisfy cosmological constraints naturally give rise to interesting signals in terrestrial neutrino oscillation experiments.Comment: 6 pages. References added, minor modification

Internet economics and policy: An Australian perspective

Publicly available information indicates that the demand and supply of Internet and Internet-related services are continuing to expand at a rapid pace. Since 1997 the number of Internet service providers (facilities-based and resellers) has increased by nearly 40 per cent; the number of points-of-presence per Internet service provider has increased by five times; the number of hosts connected to the Internet has more than quadrupled; and Internet traffic has increased from six to 10 times. The emergence of electronic commerce (e-commerce), driven by this rapid adoption of Internet services and continual technological innovation, is likely to have profound economic and social impacts on Australian society. This paper provides a detailed analysis of the impact of the Internet and e-commerce, ranging from the changes in the market structure of the telecommunications industry, its role in changing the organisation of traditional markets, the emergence of new markets, and the structural shifts to employment, productivity and trade. The paper also analyses contemporary Australian regulatory responses. IIe-commerce; internet economics

Internet traffic dynamics

The telecommunications industry has evolved at unprecedented rates with current estimates suggesting that seven percent of the world’s population now has access to the Internet. However, such growth has stimulated vigorous competition in national and international telecommunications markets leading to a price-cost margin squeeze and unsustainable rates of network expansion. This study demonstrates the reliability of established extrapolation methods for forecasting bandwidth demand and provides network managers with the opportunity to observe Internet traffic dynamics. The ability to anticipate periods of peak use and surplus capacity is likely to pay dividends in terms of a more targeted approach to network expansion plans.Telecommunications; forecasting; bandwidth

Economic determinants of global mobile telephony growth

This study examines the substitution effect between fixed-line and mobile telephony while controlling for the consumption externality associated with telephone networks. A dynamic demand model is estimated using a global telecommunications panel dataset comprised of 56 countries from 1995–2000. Estimation results show the presence of a substantial substitution effect. Additionally income and own-price elasticities are reported. Analysis of impulse responses for price, income and network size indicate substantial mobile telephone growth is yet to be realised. However, price ceilings imposed in the fixed-line network can retard the growth of the mobile network.Telecommunications; fixed-line; mobile telephony

Forecasting international bandwidth capability

M-competition studies provide a set of stylized recommendations to enhance forecast reliability. However, no single method dominates across series, leading to consideration of the relationship between selected data characteristics and the reliability of alternative forecast methods. This study conducts an analysis of predictive accuracy in relation to Internet bandwidth loads. Extrapolation techniques that perform best in M-competitions perform relatively poorly in predicting Internet bandwidth loads. Such performance is attributed to Internet bandwidth data exhibiting considerably less structure than M-competition data.Bandwidth; forecast comparisons

Visible Cascade Higgs Decays to Four Photons at Hadron Colliders

The presence of a new singlet scalar particle a can open up new decay channels for the Higgs boson, through cascades of the form h -> 2a -> X, possibly making discovery through standard model channels impossible. If a is CP-odd, its decay products are particularly sensitive to physics beyond the standard model. Quantum effects from heavy fields can naturally make gluonic decay, a -> 2g, the dominant decay mode, resulting in a h -> 4 g decay which is difficult to observe at hadron colliders, and is allowed by LEP for m_h > 82 GeV. However, there are usually associated decays with photons, either h -> 2g 2gamma or h -> 4gamma, which are more promising. The decay h -> 2g 2gamma only allows discovery of the a particle and not the Higgs whereas h -> 4gamma is a clean channel that can discover both particles. We determine what branching ratios are required for discovery at LHC and find that with 300 fb^-1 of luminosity, a branching ratio of order 10^-4 is sufficient for a large region of Higgs masses. Due to a lower expected luminosity of ~ 8 fb^-1, discovery at the Tevatron requires more than 5 x 10^-3 in branching ratio.Comment: 6 pages, 2 color figures, revtex4 forma

Subscriber churn in the Australian ISP market

Rapid growth in Internet use, combined with easy market entry by Internet service providers (ISPs), has resulted in a highly competitive supply of Internet services. Australian ISPs range in size from a few large national operators to niche ISPs focused on specialised service. With many ISPs currently not profitable, subscriber retention is an important aspect of survival. This study develops a model which relates the probability of subscriber churn to various service attributes and subscriber characteristics. Estimation results show that churn probability is positively associated with monthly ISP expenditure, but inversely related to household income. Pricing also matters with subscribers preferring ISPs which offer flat-rate pricing arrangements.

Red Crossbill Invasion of Northwestern Arkansas during 2012-2013

An irruption of Red Crossbills (Loxia curvirostra) occurred in primarily northwestern Arkansas starting in November of 2012 and lasting to the end of May of 2013. Based on recordings of call notes, most birds around Fayetteville were Type 2, the large-billed ponderosa pine crossbill, associated with a variety of conifer species. Birds recorded in Carroll County were Type 3, the small-billed western hemlock crossbill, and they were associated with small cones on shortleaf pine (Pinus echinata). One recording was obtained in Fayetteville of Type 5, the lodgepole pine crossbill, only the third recording east of the Great Plains. Crossbills at the Fayetteville Country Club were observed eating algae (Cladophora sp.) during the months of December and January, a behavior rarely reported for passerines. During March, crossbills appeared at sunflower bird feeders, which is a relatively recent phenomenon associated with low conifer seed abundance. The first two Arkansas specimens of crossbills (probably Type 3) were obtained from birds that struck windows near feeders. This is only the third recorded irruption of crossbills in Arkansas in the last 43 years, suggesting that crossbills rarely travel this far south in search of cone crops