The Arctic region is one of the most sensitive and vulnerable to climate change. The dramatic melting of Arctic ice has several negative consequences for the whole ecosystem as well as for a way of life of native people but it also creates new opportunities for the region. First, it opens up potential for exploitation of large deposits of natural resources such oil and gas. Second, it shrinks Arctic shipping routes which offer significant economic savings for many countries. These benefits has already attracted many countries, both Arctic and non-Arctic, thus resulting in potential conflict of interests. In our paper we present a mathematical approach to the problem of conflict resolution in the Arctic. First, we propose an approach how the level of interest in each part of the region should be evaluated with respect to main resources - oil, gas, fish and maritime routes. Second, we present several models of areas allocation to resolve the problem of conflict resolution. As a result, we applied several scenarios of areas allocation, evaluated their efficiency based on the total satisfaction level and identified conflict zones in the Arctic.
Though the issue of economic cycles has been subject to numerous studies, this problem has retained its high importance. What is more, the current crisis has confirmed in an extremely convincing way the point that, notwithstanding all the successes achieved by many states in their countercyclical policies, no economy is guaranteed against uncontrollable upswings and unexpected crises and recessions that tend to follow such upswings. In addition to this, the financial globalization has increased substantially the risks of such cyclical fluctuations.
The notion of economic cycles is regarded ambiguously in economic science. In modern theories, business cycles are frequently defined as fluctuations of actual output around its potential value which is achieved in full employment conditions (see, e.g., Fischer, Dornbusch, and Schmalensee 1988). However, quite frequently economics does not achieve on the rise the potential GDP volume when a recession phase starts (such situations are described in more detail in Гринин, Коротаев 2009а: ch. 1). Thus, economic cycle, in our opinion, can be defined as periodical fluctuation around medium line of production volume, where repeating phases of rise and decrease can be specified.
In the model that we propose below we have tried to briefly describe the main features of medium-term cycles of business activity, or business cycles (7–11 years) that are also known as Juglar cycles after the prominent 19th-century French economist Clement Juglar (1819–1905), who investigated these cycles in detail (Juglar 1862, 1889).
 Many economists maintain that business cycles are quite regular with the characteristic period of 7–11 years. However, some suggest that economic cycles are irregular (see, for example, Fischer, Dornbusch, and Schmalensee 1988). As we suppose, comparative regularity of business cycles is observed rather at the World System scale than in every country taken separately. This corroborates the important role of exogenous factors for the rise and progress of business cycles (for more detail see below).
 Medium-term cycles (7–11 years) were first named after Juglar in works by Joseph Schumpeter, who developed the typology of different-length business-cycles (Schumpeter 1939, 1954; see also Kwasnisсki 2008).
América Central, también llamada Centroamérica*, es un subcontinente que conecta América del Norte con América del Sur. Geográficamente se situa entre la fronreta de México y la frontera noroccidental de Colombia, rodeada por el océano Pacífico y el océano Atlántico. Políticamente se divide en los 7 países independientes de Guatemala, Belice, Honduras, El Salvador, Nicaragua, Costa Rica y Panamá. Su extensión territorial es de 523.780 km2 y su población es de unos 41.739.000 habitantes. El territorio cubre una superficie un poco mayor que la de España. Prodiga en recursos naturales, su suelo es sumamente fértil, apto para todo tipo de cultivos. El canal de Panamá además de facilitar la comunicación marítima entre dos océanos se hizo en América Central un paso obigado para los buques de todo el mundo. El subcontinente tiene todo para atraer al turismo internacional: hermosas playas, selvas, montañas, volcanes, apasibles lagos, ruinas de antiguas civilizaciones, etc. Pero la región aún está a la espera de que sus gobiernos encaren tres duros desafíos: vencer la pobreza, consolidar sus débiles democracias y apagar los odios que dejaron los largos años de guerras civiles en sus países.
In this paper, we conduct a meta-analysis of breakoff rates in mobile web surveys. We test if an optimization of web surveys for mobile devices, invitation mode (SMS vs. e-mail), survey length, expected duration in the invitation, survey design (scrolling vs. paging), prerecruitment, number of reminders, design complexity (grids, drop-down questions, sliders, images, progress indicator), incentives, an opportunity to skip survey questions, and an opportunity to select the preferred mode (PC or mobile web) have an effect on breakoffs. The meta-analysis is based on 14 studies (39 independent samples) conducted using online panels – probability-based and non-probability-based. We found that mobile optimized surveys, email invitations, shorter surveys, using a prerecruitment, more reminders, a less complex design, and an opportunity to choose the preferred survey mode decrease breakoff rates in mobile web surveys. No effect of a scrolling design, incentives, indicating expected duration in the invitation, and an opportunity to skip survey questions were found.
Во вводной статье к сборнику статей в честь 50-летия А.А. Немировского рассматривается его вклад в науку о древнем Ближнем Востоке на современном этапе.
We examine an equilibrium concept for 2-person non-cooperative games with boundedly rational agents which we call Nash-2 equilibrium. It is weaker than Nash equilibrium and equilibrium in secure strategies: a player takes into account not only current strategies but also all profitable next-stage responses of the partners to her deviation from the current profile that reduces her relevant choice set. We provide a condition for Nash-2 existence in finite games and complete characterization of Nash-2 equilibrium in strictly competitive games. Nash-2 equilibria in Hotelling price-setting game are found and interpreted in terms of tacit collusion.