Cyclic Dynamics Research Articles

The ins and outs of involuntary part-time employment

We develop and implement a protocol to measure U.S. monthly time series of involuntary part-time employment stocks and flows from 1976 until today. Armed with these new data, we provide a comprehensive account of the cyclical dynamics of involuntary part-time work. We find that the recessionary increase in involuntary part-time employment is consistently driven by a jump in the transition probability from other employment states to involuntary part-time employment, and a drop in the reverse transition probability. We compare the dynamics of unemployment and involuntary part-time employment to argue that they reflect the operation of distinct labor-adjustment channels. While unemployment dynamics are driven by movements in job creation and destruction, the dynamics of involuntary part-time employment reflect changes in employers’ labor utilization.

Bamboo phenology and life cycle drive seasonal and long‐term functioning of Amazonian bamboo‐dominated forests

Abstract Bamboo‐dominated forests (BDF) extend over large areas in the drought‐prone Southwestern Amazon, yet little is known about the dynamics of these ecosystems. Here, we investigate the hypothesis that bamboo modulates large‐scale ecosystem dynamics through competition with coexisting trees for water. We examined spatio‐temporal patterns of remotely sensed metrics (Enhanced Vegetation Index [EVI], Normalized Difference Moisture Index [NDMI]) in >300 Landsat images as proxies for canopy leaf phenology and water content at two time scales: (1) a complete bamboo life cycle (~28 years), and (2) the seasonal cycle; and at two spatial scales: (a) comparing adjacent areas of BDF vs. Terra‐firme forests (TFF) to investigate regional dynamics, and (b) comparing the vegetation classes of bamboo, trees in BDF, and trees in TFF to investigate the effects of bamboo on coexisting trees. At the regional scale, BDF showed higher EVI (leaf area density) and lower NDMI (water content) than nearby TFF but these differences disappeared as bamboo died, suggesting a strong influence of bamboo life stage in the functioning of these forests. BDF seasonal cycle showed a bimodal EVI pattern as trees and bamboos had asynchronized leaf production peaks. At the scale of vegetation classes, trees in BDF showed lower NDMI (i.e. water content) than trees in TFF except after bamboo mortality, indicating a release from competition with bamboo for water. Canopy water content of trees in BDF was also reduced during bamboo dry‐season greening (increased EVI ~ leaf production) due to increased water demands. Nevertheless, long‐term and seasonal phenology of trees in BDF did not differ from that of trees in TFF suggesting a potential selection for drought‐tolerant trees in BDF. Synthesis. Bamboo‐dominated forests have received less attention than other Amazonian forests and their functional dynamics are commonly ignored or misinterpreted. Using remote sensing to characterize forest phenology and water content, we show the distinctive seasonal and long‐term dynamics of BDF and coexisting trees and the importance of bamboo competition for water in shaping this ecosystem. Our results suggest a potential selection for drought‐tolerant trees in BDF since they maintain the same EVI as trees in bamboo‐free forests but with lower water content. A better characterization of BDF and their cyclical dynamics is crucial for accurately interpreting Amazonian forests' responses to extreme climatic events such as high temperatures and droughts.

Політичні цикли в умовах формування інформаційно-мережевого суспільства

In the cyclical dynamics of the capitalist world system, politics and economics are closely intertwined, which is manifested in the development of political business cycles of individual countries, as well as in the development of cyclical political and economic processes in the long run on a global scale. The development of political business cycles is due to the influence of interrelated factors - competition of political forces, economic expectations and political preferences of voters. The immanent to the capitalist world-system deep internal contradictions lead to a variety of forms of long-term socio-economic cycles, including such a form as political cycles of a global nature. In the modern conditions of transition from the industrial-market system to the information-network society, the factors continue to exist and the contradictions emerge that both lead to the development of political cycles. Technical and technological transformations that contribute to the formation of information and network society, are strengthening the possibilities of ideological and propaganda activities that affect the cyclical political and economic processes. In such conditions, political cycles are becoming more and more emergent, which is largely due to the influence of social networks, computer games, and "new media" on people's political preferences and their political activity. The cyclical processes of establishing economic and political hegemony in the capitalist world system determine the dominance of the political cycles of leading countries over those of less developed countries. Improving production and dissemination technologies enhances the ability of leading countries to influence the political cycles of less developed countries, and the use of "soft power" is becoming an increasingly important tool of geopolitical struggle in the process of deployment of long-term global political cycles.

Cyclic dynamics of misfires and partial burns in a dilute spark-ignition engine

This study investigates the cyclic dynamics of cumulative heat release data past the edge of stability in a dilute spark-ignition engine. Emphasis is placed on analyzing the cyclic dynamics near the dilute limit where partial burns and misfires are frequent. These events are often followed by a higher-energy cycle due to the feed-forward mechanism present in the residual gases. These patterns are deterministic and increase the coefficient of variation to undesirable levels. Symbol sequence analysis was used to investigate the cyclic dynamics of these low–high patterns. The heat release was partitioned on an energy basis to give physical meaning to each partition and each sequence created when analyzing the symbol sequence results. This partitioning method provided insight into the differences in the dynamics when operating in the misfire or partial burn regime. These differences could impact the control method used.

Seasonality in ecology: Progress and prospects in theory

Seasonality is an important feature of essentially all natural systems but the consequences of seasonality have been vastly underappreciated. Early work emphasized the role of seasonality in driving cyclic population dynamics, but the consequences of seasonality for ecological processes are far broader. Yet, seasonality is often not explicitly included in either empirical or theoretical studies. Many aspects of ecological dynamics can only be understood when seasonality is included, ranging from the oscillations in the incidence of childhood diseases to the coexistence of species. Through several case studies, we outline what is now known about seasonality in an ecological context and set the stage for future efforts. We discuss various approaches and tools for incorporating seasonality in mathematical models. We argue, however, that these tools are still limited in scope and more easily-accessible approaches need to be developed.

Climate change increases predation risk for a keystone species of the boreal forest

Canada lynx (Lynx canadensis) and snowshoe hares (Lepus americanus) form a keystone predator–prey cycle that has large impacts on the North American boreal forest vertebrate community. Snowshoe hares and lynx are both well-suited for snowy winters, but climate change-associated shifts in snow conditions could lower hare survival and alter cyclic dynamics. Using detailed monitoring of snowshoe hare cause-specific mortality, behaviour and prevailing weather, we demonstrate that hare mortality risk is strongly influenced by variation in snow conditions. Although predation risk from lynx was largely unaffected by snow conditions, coyote (Canis latrans) predation increased in shallow snow. Maximum snow depth in our study area has decreased 33% over the last two decades and predictions based on prolonged shallow snow indicate that future hare survival could resemble that seen during population declines. Our results indicate that climate change could disrupt cyclic dynamics in the boreal forest. Monitoring of snowshoe hare (Lepus americanus) cause-specific mortality and behaviour reveals increased risk of predation from coyote (Canis latrans) in shallow snow. This could disrupt the keystone Canada lynx (Lynx canadensis)–hare predator–prey cycle in North American boreal forests.

Predicting Turning Points of the Russian Economic Cycle Using Composite Leading Indicators

Thearticleprovidesa brief overview of the background of constructing composite leading indicators (CLI) for Russia; the paper defines key indicators which currently are calculated and published monthly; they can be put in practice to monitor the Russianeconomy. The underlying methodological approaches are analyzed, along with their advantages and disadvantages. The importance of accounting for a factor of regular or irregular updates and revisions of methods for calculating the CLI is emphasized. Due to them not only the current but also the “historical” dynamics of the indices occasionally change. The paper compares various CLI components and reveals both similarities and differences in the notion of the cyclical dynamics of individual components, reaching the point that the same indicators depending on the methodology are considered as leading, or as lagging. A set of “core” indicators included in the calculation of almost all Russian CLIs is determined; the author also noted those indicators that are widely used in other countries but not yet in Russia, for various reasons.Specialattentionispaidtotheproblemsofdatingeconomiccycleturningpoints,inparticular,thosearisingfromdifferentnotionsofthevery concept of the economic cycle. Dating using formal statistical methods, firstly, is mostly determined by purely technical (and not substantive) nuances, and secondly, it often changes retroactively when revising historical time series. Analysis of global experience indicates that the way out of this impasse can be the detecting of cyclical turning points based on the decisions of the special expert council, whose sole tasks include dating cyclical peaks and troughs. The article describes methodological approaches that the Economic Cycle Dating Committee (Russian Dating Committee, RDC) under the Association of Russian Economic Think Tanks (ARETT), is supposed to follow.The final part of the article analyzes the ability of various Russian CLIs to timely warn when a new phase of the economic cycle is approaching, especially the impending recession. It is shown that expert opinions on the future dynamics of the Russian economy, contained in monthly press releases, are often more accurate than the conclusions that can be obtained based on the CLI trajectory using purely formal decision rules. On this basis, it is concluded that the existing Russian CLIs can be improved; this calls for clarification and finally fixing the dating of cyclical turning points (peaks and troughs), as well as for conducting additional research to identify various economic and financial indicators as the leading, synchronous or lagging indicators of the Russian economic cycle.

Cycle populations dynamics of harmful insects

We studied the reproduction cycles of 39 pest insect species and revealed that they, being cyclical and polycyclic in nature, are not strictly periodic and occur at different intervals. Moreover, we registered the outbreaks in their numbers in the periods with minimum and maximum of solar activity. The frequencies of the mass reproductions during the years of benchmarks were 2.5–3.0 times higher than the frequencies during the other years for the period of 1854–1985. We asserted that the synchronism of 70 species mass reproductions took place in Ukraine during some period with the years of sharp changes in the solar activity. The global synchronization of insect mass reproductions cannot be only explained by the weather factors since they are unlikely even within the same region. We suggested that the population cycles are self-oscillations of the biological systems synchronised by the solar activity, which can create the double effect: the “cyclic background” in the Earth changes and a part of the fractures of the long-term course distorting this “cyclic background”. The over helming majority of insect mass reproductions began in dry periods, and the droughts are synchronous with the dynamics of the solar activity. We believed that the cyclic character and recurrence are the universal properties of the development and functioning of any natural systems in space and time. This conclusion could be the conceptual basis for regularities in long-term recurrence of mass insect reproduction. Our idea of cyclic population dynamics reflects its descriptive, explanatory, prognostic and synthesizing functions and combines the previously proposed climatic and trophic theories. We developed the method and algorithms for a long-term forecast of insect mass reproductions on cyclic character of the population dynamics. According to the modern concepts of nonlinear dynamics (synergetics), the mass reproductions of insects are definitely programmed in present and future.

Post-Pandemic Scenarios of Economic Development of Developed Countries and Russia

Amid the Kondratiev cycle's downward slope movement and global pandemic, a recession in many countries is Likely to Lead to a deep long-term economic crisis. The aim of the article is to study the simplest recession indicators in developing and developed countries, economic-recovery measures, and economic development scenarios. The objectives of the paper are to study current economic situations in different countries, including Russia; identify measures to prevent a recession in developing and developed countries; evaluate possible economic development scenarios with regard to the cyclical dynamics in the current climate. The authors used methods of analysis, modelling, monitoring of major economic indicators based on the data of past recessions and other crises. The results of the research show different scenarios of economic growth depending on the number of Covid-19 cases and the effectiveness of government’s responses to the pandemic; a correlation between monetary and fiscal policies in overcoming crisis; monetary policy priorities necessary for economic recovery; problems and prospects of monetary and fiscal policy implementation. The authors concluded that GDP, unemployment, and inflation rate are key indicators for the evaluation of the current and future money, credit, and production-related events. Proactive measures ensure a smoother average economic growth. Both monetary and fiscal policy have advantages and disadvantages. Proactive measures, in particular, inevitably cause two time lags: in the reaction to a recession and in the effectiveness of implemented measures. The governments and central banks must be proactive in overcoming the economic recession and providing support to the citizens.

Prognostication in plant protection. Review of the past, present and future of nonliner dynamics method

By carrying out a theoretical synthesis of the information on the regularities of population dynamics of some insect pests of agricultural plants and based on the past and present the authors have analysed the dynamics of many years in the number of the insect populations. An attempt to determine the presence of synchronism of outbreaks of the insects’ mass reproduction with the years of sharp changes in the solar activity has been made; the relationship between the changes in the number of the insects and meteorological and heliographic factors has been analysed. An analysis of the dynamics of the sun pest reproduction taking into account the duration of sunshine on the materials of one of the outbreaks (local population) in the Kupiansk district of the Kharkiv region showed the unreliability of this index as a predicate of the prognosis; and the reproduction rate of the local population of the sun pest does not change depending on the duration of the solar radiance. It is determined that this principle is also unsuitable for forecasting the dynamics in the number of this pest. The linear differential equations, in which not only the meteorological factors but also the indices of the solar activity (global factor) were used as variables were unsuitable for prognostication the dynamics in the number of the insects. The examples listed in the article confirm the fundamental regularity, namely the polycyclic dynamics of various natural systems and the synchronism in their development. The synchronization is inevitable because all objects of inanimate and living nature consist of the same chemical elements, and the conservation and conversion of energy is universal in nature. Based on the methodology of the cyclic dynamics it is possible to develop the algorithms for prognostication the regular mass reproduction of harmful insects.

Corporate Diplomacy Strategy and Instruments; With a Discussion about “Corporate Diplomacy and Cyclical Dynamics of Open Innovation”

This paper delves into the manner in which some Multinational Corporations (MNCs) manage corporate diplomacy as a catalyst of their political, social, and cultural influence in foreign markets. Once the related literature is reviewed, the qualitative Focus Group technique is applied by creating two teams of nine business internationalization experts, chosen amongst university professors; representatives of institutions and organizations, such as Chambers of Commerce or embassies; MNCs’ executives and lobbyists; and high-level representatives of Spanish state diplomacy. This contribution verifies that corporate diplomacy is known and clearly distinguished from other similar functions within the company in Spain; nevertheless, it is admitted that, in the case of Spanish MNCs, the arrival of corporate diplomacy is delayed. Secondly, we present the four key instruments to exert influence and, in turn, the most necessary ones to implement corporate diplomacy strategies: networking with external stakeholders, competitive intelligence, corporate reputation, and lobbying actions. Additionally, this paper shows that some MNCs coexist with other types of diplomacy—e.g., state or political, public and commercial diplomacy, although most do not yet do so autonomously, especially the Spanish MNCs. However, MNCs foster the perception that they assume, in a certain way, the role of the nation-states. This paper’s contribution is to establish that the current cross-border relational framework requires corporations to develop a true foreign policy and acquire a diplomatic know-how to strategically manage their influence in the countries where they operate so that they can obtain a “social license to operate” and generate favorable business environments. Finally, a short discussion about possible connections between corporate diplomacy and cyclical dynamics of open innovation is included, where engagement of external stakeholders and culture understanding are the main points in common identified.

Cyclical drivers of euro area consumption: What can we learn from durable goods?

We study the cyclical dynamics of consumption in the euro area (EA) and the large EA countries by distinguishing durable from nondurable expenditures. We adopt a theoretical partial equilibrium framework to justify the identification strategy of our empirical model, a time-varying parameter structural vector autoregression (TVP-SVAR). Following the main insight from the theoretical model, that liquidity constraints induce important interactions between durables and nondurables, we distinguish durable-specific demand and supply shocks, while taking into account monetary and credit conditions. Our main findings are: (i) durables react faster and more strongly than nondurables after monetary shocks in the euro area and in the largest EA countries, a confirmation of an outcome commonly reported for the US; (ii) there is a large degree of cross-country heterogeneity in how different factors (including durable-specific ones) explain consumption; (iii) the strength of spillovers from durable to nondurable consumption, as predicted by theory, is empirically correlated with how much households across countries are likely to be liquidity constrained.

Zika virus envelope – heat shock protein A5 (GRP78) binding site prediction

Recent studies reported the association of the Zika virus (ZIKV) with a stress response receptor on the host cell membrane that facilitates viral entry. This host receptor was the heat shock protein A5 (HSPA5), also termed glucose-regulating protein 78 (GRP78). In this study, structural bioinformatics and molecular dynamics simulations were utilized to suggest the binding site of ZIKV envelope protein during the interaction with cell-surface GRP78. The Pep42 cyclic peptide was used as a profiler, as it was reported earlier, to target GRP78 on the cancer cell membrane selectively. Sequence and structural alignments show that part of the ZIKV envelope protein (C308-C339 region), in addition to its cyclic nature, has somehow sequence and structural similarities to the cyclic Pep42. Three amino acids in the ZIKV envelope were identical to those in the Pep42 peptide. Cyclic peptides dynamics are studied, and its binding to GRP78 is predicted. Protein-protein docking is further performed to explore the binding characteristics of the ZIKV envelope to GRP78. Results revealed that the binding was favorable between ZIKV envelope protein and GRP78. The docking pose revealed the involvement of the substrate-binding domain ß of GRP78 and the domain III of the ZIKV envelope protein in viral recognition for the host-cell.

DYNAMICS OF INNOVATIVE COMPETITION

The subject of this work is the problem of the dynamic interaction of innovative products in a competitive market. Sustainable economic growth is currently impossible without increasing the competitiveness of enterprises and industries, largely determined by the strengthening of the competitive environment. As a result of the competition of economic agents for achieving various advantages in the markets, new products are created and improved with the corresponding development of technologies. In the analysis of previous publications, the role of the national innovation policy of the state in the system of forming priorities of investment activity in market conditions is noted. The purpose of the work is to study the features of building competition models of innovative processes. It should be emphasized that economic systems have a complex and heterogeneous structure with a hierarchical pattern of interaction of endogenous and exogenous factors. A common feature of many balance models of a market economy is the presence of autocatalytic components that determine the growth mechanisms of an innovative product. The article solves the problem of constructing and analyzing the behavioral properties of a mathematical model of competition between two economic entities in a common market. As a prototype for the model of endogenous homeodynamic system, the widely known mathematical model "predator-prey" is used in population dynamics. This model is a system of two ordinary differential equations with quadratic nonlinearities, which has several equilibrium positions and has a behavior with a change in the nature of stability. Research methods are based on the mathematical apparatus of economic synergetics and the theory of stability of nonlinear dynamic systems. As a result, the conditions under which the self-oscillating mode is implemented in the vicinity of the equilibrium state with the appearance of one or more limit cycles are specified. It has been established that the maximum number of limit cycles in the system under study around the equilibrium position is three. The subject analysis of the bifurcation properties of the cyclic dynamics of competitive interaction is carried out, the boundaries of stability loss by the equilibrium position are determined. Conclusions. The behavioral nature of the dynamics of innovation processes is changing significantly and it is possible to implement a leap transition from monotonous economic growth to relaxation fluctuations.

Beyond rock–paper–scissors systems — Deterministic models of cyclic ecological systems with more than three species

We consider cyclic ecological systems consisting of more than three species, extending the well-studied three-species rock–paper–scissors (RPS) system. For such systems alliance and partial alliance states consisting of non-competing species can form, a phenomenon not present in classical RPS systems. We develop, analyze and simulate a May–Leonard type model accounting for cyclic dynamics and spatial diffusion. We analyze in detail four-species and five-species systems, determine dynamics for both spatially homogeneous initial conditions (i.e., ode models) and the propagation and interaction of patches of different species driven by diffusion and the cyclic dynamics (pde models). We show markedly different behavior between the four-and five-species models, with alliance states as stable steady states for the former whereas both coexistence of all species and heteroclinic cycles are possible stable outcomes for the latter. Finally, we discuss the extension of this even/odd split to systems with more than five species.

Aggregate Uncertainty and the Micro-Dynamics of Firms

Using firm level micro-data, I find evidence that firms with lower growth prospects are more sensitive to aggregate shocks. I interpret these findings using a model of demand accumulation and endogenous entry and exit decisions, which I then estimate on French data. The resulting cyclical dynamics of firms provide an explanation for the observed counter-cyclical dispersion in firms' growth rates. They suggest that cyclical dispersion is the result of a pre-existing and persistent characteristic of the firm and caution against its use as a proxy for time-varying uncertainty. The estimated negative correlation between a firm's sensitivity to aggregate shocks and its expected future growth rate is shown to have important consequences for the cyclical characteristics of entering and exiting firms. The quantitative model suggests that this compositional effect is sizeable and equivalent to around 10.5% of the drop in aggregate employment between 2008 and 2009.

Анализ долговременных тенденций роста древостоев ели европейской в связи с возможным изменением климата (на примере Ленинградской области)

The Lisino training and experimental forest of the Saint-Petersburg State Forest Technical University was chosen as a study area. The forest is located in the central part of the Leningrad region and has a high level of protection as a forest of scientific and historical value. According to the official data, mean annual temperature in the region increased by 0.6 °C within 10 years as well as precipitation. The impact determination of changing climate conditions on Norway spruce trees growth was the aim of this study. Three most representative compartments dominated by Norway spruce (Picea abies (L.) Karst.) were selected for data collection. Core samples were taken by the Pressler increment borer from 107 dominant trees while climatic data were obtained from the nearest weather stations. Tree rings were measured and analyzed using WinDendro software while climate data were processed by Microsoft Excel. Tree ring data cover the time interval from 1848 to 2011, each ring was characterized by width, calendar year, age and diameter of the tree. Radial growth was analyzed within age and diameter classes. Annual rings widths were varied from 0.1 to 6 mm. There was a positive trend in age classes of 0-20, 21-40 and 41-60 years old. The growth was very slow in the age classes of 61-80, 81-100 and >100. Diameters are larger in the age classes of 20-40 and 41-60 as compare to the local diameter growth table which was developed in the 19th century. Diameters for age classes older than 41-60 years were less than prescribed by the diameter growth table. Annual rings width for all age classes also demonstrate cyclic dynamics, moreover, the decline in growth sometimes occurred in recent decades. Multiple regression was used for developing the response function of growth to changes in climatic conditions. There was revealed a high correlation (90 %) and low influence of vegetation period climate data on growth during 1848–2011 (0.08102 mm/°C and 0.00085 mm/mm). Likewise, analysis shows that growth is higher in young and middle-aged than mature and over mature stands. Overall, climate change impact has a positive effect on the radial growth of Norway spruce for the studied area, however, not for all age and diameter classes.For citation: Alekseev A.S., Sharma S.K. Long-Term Growth Trends Analysis of Norway Spruce Stands in Relation to Possible Climate Change: Case Study of Leningrad Region. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 3, pp. 42–54. DOI: 10.37482/0536-1036-2020-3-42-54

Lending relationships and labor market dynamics

Motivated by a negative link between credit spreads and labor force participation (LFP) and a positive link between these spreads and unemployment over the business cycle, we study the role of LFP as an amplification mechanism of financial shocks in a labor search model with endogenous LFP, lending relationships, and credit-market disruptions. Amid aggregate productivity and financial shocks that replicate the empirical volatility of LFP and credit spreads, the model produces highly volatile unemployment and vacancies, countercyclical credit spreads and unemployment, and procyclical LFP. When we quantitatively match the cyclical behavior of credit spreads, the interaction between endogenous LFP and financial shocks gives rise to much sharper vacancy fluctuations and plays a key role in generating quantitatively factual cyclical labor market dynamics.

Ambiguous business cycles: A quantitative assessment

In this paper, we examine the cyclical dynamics of a Real Business Cycle model with ambiguity averse consumers and investment irreversibility using the smooth ambiguity model of Klibanoff et al. (2005, 2009). Ambiguity of belief about the productivity process arises as agents do not know the process driving variation in aggregate TFP, and they must make inferences regarding the true process at the same time as they infer the behavior of the unobserved temporary component using a Kalman filtering algorithm. Our findings may be summarized as follows. First, the standard business cycle facts hold in our framework, which are not altered significantly by changes in the degree of ambiguity aversion. Second, we demonstrate a role for information and learning effects, and show that lower initial ambiguity or greater confidence coupled with learning dynamics lowers the volatility and increases the persistence in all of the key macroeconomic variables. Third, comparing the performance of our model to the New Keynesian business cycle model of Ilut and Schneider (2014) with maxmin expected utility, we find that the version of their model without nominal and real frictions turns out to have limited success at matching the moments for the quantity variables. In the maxmin expected utility framework, the worst case scenario instills too much caution on the part of agents who, in the absence of a key set of nominal and real frictions, end up excessively reducing their responses to TFP shocks.

Is There a Relationship between the Chitty Effect and the Types of Population Dynamics?

Thirty-year studies of populations of eight shrew species in the Middle Yenisei taiga have shown that at the late 20th century the population dynamics had a pronounced cyclic character, but in the 21st century cyclic dynamics changed with fluctuating one. The analysis of the dependence of the animal body weight on the population density have revealed that under cyclic dynamics at the peaks of the population, the animal's body weight is significantly higher than that at population decline, i.e., the corollary from the Chitty hypothesis (the Chitty effect) is observed. In populations with fluctuating dynamics such regularity has not been observed.