scholarly journals How ecosystems recover from pulse perturbations: A theory of short- to long-term responses

2017 ◽  
Author(s):  
J.-F. Arnoldi ◽  
A. Bideault ◽  
M. Loreau ◽  
B. Haegeman
Keyword(s):  
Rare Species ◽  
Empirical Studies ◽  
Abundant Species ◽  
Theoretical Studies ◽  
Short Term ◽  
Median Response ◽  
Return Rates ◽  
Theoretical Predictions ◽  
Recovery Dynamics

AbstractQuantifying stability properties of ecosystems is an important problem in ecology. A common approach is based on the recovery from pulse perturbations, and posits that the faster ecosystems return to their pre-perturbation state, the more stable they are. In theoretical studies the recovery dynamics are often collapsed into a single quantity: the long-term rate of return, called asymptotic resilience. However, empirical studies typically measure the recovery dynamics at much shorter time scales. In this paper we explain why asymptotic resilience is rarely representative of the short-term recovery. First, we show that, in contrast to asymptotic resilience, short-term return rates depend on features of the perturbation, in particular on the way its intensity is distributed over species. We argue that empirically relevant predictions can be obtained by considering the median response over a set of perturbations, for which we provide explicit formulas. Next, we show that the recovery dynamics are controlled through time by different species: abundant species tend to govern the short-term recovery, while rare species often dominate the long-term recovery. This shift from abundant to rare species typically causes short-term return rates to be unrelated to asymptotic resilience. Finally, we discuss how these findings might help to better connect empirical observations and theoretical predictions.

A Note Concerning the Dynamics of Government Bond Yields

2021 ◽  
pp. 056943452098827
Author(s):  
Tanweer Akram
Keyword(s):  
Interest Rate ◽  
Financial Markets ◽  
Yield Curve ◽  
Empirical Studies ◽  
State Theory ◽  
Government Bond ◽  
Bond Yields ◽  
Short Term ◽  
Government Bonds

Keynes argued that the central bank can influence the long-term interest rate on government bonds and the shape of the yield curve mainly through the short-term interest rate. Several recent empirical studies that examine the dynamics of government bond yields not only substantiate Keynes’s view that the long-term interest rate responds markedly to the short-term interest rate but also have relevance for macroeconomic theory and policy. This article relates Keynes’s discussions of money, the state theory of money, financial markets, investors’ expectations, uncertainty, and liquidity preference to the dynamics of government bond yields for countries with monetary sovereignty. Investors’ psychology, herding behavior in financial markets, and uncertainty about the future reinforce the effects of the short-term interest rate and the central bank’s monetary policy actions on the long-term interest rate. JEL classifications: E12; E40; E43; E50; E58; E60; F30; G10; G12; H62; H63

scholarly journals Post-Acquisition Performance of Emerging Market Firms: A Multi-Dimensional Analysis of Acquisitions in India

2021 ◽  
Vol 14 (12) ◽  
pp. 567
Author(s):  
Arindam Das
Keyword(s):  
Structural Equation ◽  
Emerging Market ◽  
Empirical Studies ◽  
Short Term ◽  
Firm Level ◽  
Acquisition Performance ◽  
Long Term Performance ◽  
Term Performance ◽  
A Performance

M&A performance is a multifaceted, compound construct with no overarching factor that captures all different dimensions. This paper examines the concept of acquisition performance and proposes a model that links firm-level factors and transaction parameters with firms’ short-term and long-term performance, extending to financial-, market- and innovation measures. Building on past empirical studies on the influence of various factors on M&A performance, a multi-dimensional structural equation model has been developed and it has been tested with a dataset on acquisitions in the Indian technology sector over a period of ten years. The results suggest that: (a) smaller acquirers with higher book value and leveraged firms demonstrate better long-term performance; (b) contrary to established understanding, short-term market returns are not influenced by deal parameters; (c) majority stake purchases show relatively lesser gains—suggesting the possible presence of post-acquisition integration issues and, (d) acquirers with high intangible assets continue to do well on innovation performance post-acquisition. By indicating situations and conditions under which an acquisition would potentially lead to a performance gain for the acquirer, these results provide significant insight to practitioners pursuing M&As for growth opportunities.

The early bird catches the retirement savings

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lucía Rey-Ares ◽  
Sara Fernández-López ◽  
María Milagros Vivel-Búa ◽  
Rubén Lado-Sestayo
Keyword(s):  
Social Factors ◽  
Cognitive Abilities ◽  
Design Methodology ◽  
Empirical Studies ◽  
Planning Horizon ◽  
Retirement Savings ◽  
Short Term ◽  
Relevant Variable ◽  
Content Type

Purpose This paper aims to investigate whether individuals’ planning horizon influences their decision to save privately for their retirement. Design/methodology/approach Focussing on Spain, this empirical research uses the fifth wave of the Survey of Health, Ageing and Retirement in Europe (SHARE)[1]. Logit models are estimated considering variables related to demographic characteristics, economic situation, education and cognitive abilities and psychological and social factors. Findings The results confirm that the planning horizon significantly influences the decision to save for retirement. Long-term planners are more likely to save for retirement than short-term planners. Originality/value Although previous literature has identified the planning horizon as a relevant variable in the decision to save for retirement, few empirical studies have evaluated their impact. This paper shows that it is important to develop habits of financial planning in societies, especially in societies with a prominent orientation towards the present.

scholarly journals Understanding beverage taxation: Perspective on the Philadelphia Beverage Tax’s novel approach

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Ryan M. Kane ◽  
Vasanti S. Malik
Keyword(s):  
Policy Process ◽  
Empirical Studies ◽  
Health Impact ◽  
Short Term ◽  
Sugar Sweetened Beverage ◽  
Novel Approach ◽  
Global Trend ◽  
Health Impact Assessments ◽  
Political Entrepreneurs

Despite the growing global trend of sugar-sweetened beverage (SSB) taxes for their potential as an untapped source of revenue and as a public health boon, these legislative efforts remain controversial. Multiple articles have reviewed this trend in recent years from modeling of long-term impacts to short-term empirical studies, yet most comprehensive, long-term health impact assessments remain forthcoming. These multi-faceted efficacy studies combined with case-based assessments of the policy process, descriptive pieces highlighting unique features of the policy and reflective perspectives targeting unanswered questions create a comprehensive body of literature to help inform present and future legislative efforts. The passage of the Philadelphia Beverage tax required a mix of political entrepreneurs, timing and context; while uniquely employing a nonpublic health frame, specific earmarking and a broadened scope with the inclusion of diet beverages. This perspective on the Philadelphia Beverage Tax will describe the passage and novel features of the Philadelphia Beverage Tax with a discussion of the ethical questions unique to this case.

A comparative analysis of the implications of the Islamic religion on corporate capital structures of firms in emerging market countries

2014 ◽  
Vol 7 (3) ◽  
pp. 277-287 ◽  
Author(s):  
Theresa Gunn ◽  
Joshua Shackman
Keyword(s):  
Emerging Market ◽  
Empirical Studies ◽  
Short Term ◽  
Content Type ◽  
Corporate Capital ◽  
Muslim Countries ◽  
Total Debt ◽  
Islamic Religion ◽  
The Impact

Purpose – The purpose of this study is to examine the impact of the Muslim religion on firm capital structure. Design/methodology/approach – The authors compare financing patterns in Muslim versus non-Muslim countries using 658 firms in 16 countries covering a period of seven years. Findings – No significant differences between Muslim and non-Muslim countries were found in terms of total debt ratios. However, significant differences were found in the choice of short-term versus long-term debt, with firms in Muslim countries showing a strong preference for short-term debt. Research limitations/implications – The findings confirm existing theories on the impact of the Islamic religion on short-term versus long-term debt preferences. However, the findings concerning the lack of an impact of the Islamic religion on total debt preferences are surprising and contrary to existing theories. Practical implications – Firms in Muslim countries appear to have the flexibility to adopt overall leverage ratios comparable to those in non-Muslim countries. However, firms in Muslim countries may be disadvantaged in that there appear to be impediments to the use of long-term debt. Originality/value – This paper presents one of the first empirical studies of the impact of the Muslim religion on corporate financing choices across a large cross-section of firms in Muslim and non-Muslim countries.

scholarly journals Effects of handling and short-term captivity: a multi-behaviour approach using red sea urchins, Mesocentrotus franciscanus

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6556 ◽  
Author(s):  
Aneesh P.H. Bose ◽  
Daniel Zayonc ◽  
Nikolaos Avrantinis ◽  
Natasha Ficzycz ◽  
Jonathan Fischer-Rush ◽  
...  
Keyword(s):  
Red Sea ◽  
Sea Urchins ◽  
Abundant Species ◽  
Ecosystem Functions ◽  
Short Term ◽  
Induced Stress ◽  
Aggregation Behaviour ◽  
Fitness Consequences ◽  
Term Monitoring

Understanding the effects of captivity-induced stress on wild-caught animals after their release back into the wild is critical for the long-term success of relocation and reintroduction programs. To date, most of the research on captivity stress has focused on vertebrates, with far less attention paid to invertebrates. Here, we examine the effect of short-term captivity (i.e., up to four days) on self-righting, aggregation, and predator-escape behaviours in wild-caught red sea urchins, Mesocentrotus franciscanus, after their release back into the wild. Aggregation behaviour, which has been linked to feeding in sea urchins, was not affected by handling or captivity. In contrast, the sea urchins that had been handled and released immediately, as well as those that were handled and held captive, took longer to right themselves and were poorer at fleeing from predators than wild, unhandled sea urchins. These results indicate that handling rather than captivity impaired these behaviours in the short term. The duration of captivity did not influence the sea urchin behaviours examined. Longer-term monitoring is needed to establish what the fitness consequences of these short-term behavioural changes might be. Our study nevertheless highlights the importance of considering a suite of responses when examining the effects of capture and captivity. Our findings, which are based on a locally abundant species, can inform translocation efforts aimed at bolstering populations of ecologically similar but depleted invertebrate species to retain or restore important ecosystem functions.

Fluctuations of rodent populations in response to rainfall and fire in a central Australian hummock grassland dominated by Plectrachne schinzii

1996 ◽  
Vol 23 (3) ◽  
pp. 289 ◽  
Author(s):  
R Southgate ◽  
P Masters
Keyword(s):  
Small Mammal ◽  
National Park ◽  
Fold Increase ◽  
Abundant Species ◽  
Dry Period ◽  
Short Term ◽  
Rainfall Events ◽  
The Impact ◽  
Rodent Populations

Fluctuations in the composition and abundance of a small-mammal assemblage were studied in a hummock grassland dominated by Plectrachne schinzii at Watarrka National Park from 1988 to 1993. During this period an experiment was conducted to examine the short-term effects of fire on the rodents. We caught three species of rodent (Pseudomys hermannsburgensis, Notomys alexis and Mus domesticus). All species reached their greatest density in spring 1989 during an exceptionally wet period that extended from mid- 1988 to 1990. P. hermannsburgensis was the most abundant species and showed a 10-fold fluctuation in numbers over the sample period; N. alexis was the next most abundant species and showed a 5-fold increase but the population took longer to decline. M. domesticus was recorded only during the period of high rainfall. The number of M. domesticus was significantly less on the burnt plots than on the unburnt plots. Neither P. hermannsburgensis nor N. alexis showed significant differences between burnt and unburnt plots. This study illustrates the impact of rainfall events on the composition and density of small-mammal populations in spinifex grasslands in central Australia. Our results lead to the prediction that rodent populations will achieve densities in the order of 10 individuals ha-' or more in regions that experience three consecutive 6-month periods each with rainfall at 150% of the long-term average. This sequence apparently needs to follow a dry period where rainfall is no more than 85% of the long-term annual average for two consecutive 12-month periods.

scholarly journals Pre-existing long-term memory facilitates the formation of visual short-term memory

2021 ◽  
Author(s):  
Weizhen Xie ◽  
Weiwei Zhang
Keyword(s):  
Task Performance ◽  
Short Term Memory ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Neural Data ◽  
Visual Short Term Memory ◽  
Open Questions ◽  
Theoretical Predictions

The current chapter aims to solidify converging observations in the literature concerning the contribution of pre-existing LTM to the formation of VSTM. Our approach primarily focuses on identifying conditions under which pre-existing LTM can facilitate VSTM (Xie & Zhang, 2017c), instead of the traditional focus on whether or not pre-existing LTM affects VSTM task performance (e.g., Brady, Störmer, & Alvarez, 2016; Quirk, Adam, & Vogel, 2020). This approach could provide a novel context for the development of theories about VSTM, LTM, and their interactions. Here, we will begin with some theoretical predictions of the roles of pre-existing LTM in VSTM formation. Next, we will summarize converging evidence from behavioral and neural data in support of some of these predictions. Finally, we will discuss mechanisms underlying these empirical observations and propose some open questions for future investigations.

scholarly journals Gårsdagens suksess – morgendagens begrensning? Strategisk relevant handlingsrom: En rikere forståelse av leders handlingsrom

2020 ◽  
pp. 111-134
Author(s):  
Jarle Bastesen ◽  
Birthe Kåfjord Lange
Keyword(s):  
Conceptual Model ◽  
Empirical Studies ◽  
Large Degree ◽  
Managerial Discretion ◽  
Future Research ◽  
Leadership Studies ◽  
Short Term ◽  
Relevant Alternatives ◽  
Future Challenges

Managerial discretion is said to be a fundamental condition for effective leadership. Studies of managerial discretion have to a large degree focused on the magnitude of managers’ discretion and how different factors influence managers’ perceived level of discretion (Hambrick, 2007; Hambrick & Finkelstein, 1987; Hutzschenreuter & Kleindienst, 2013). In this chapter, we argue that it is insufficient to study the size of managers’ room for discretion. We also need to understand the content included in leaders’ discretionary rooms. In a study of ten successful logistics companies, one of which was studied more in-depth, we find that the managers perceive their room for managerial discretion as large. However, the alternatives considered are to a large extent operational and short-term, at the expense of more long-term, strategically relevant alternatives facing future challenges. Hence, we develop the concept “strategically relevant managerial discretion”, which, in addition to the alternatives that managers are aware of and that are acceptable for the mangers’ stakeholders, also includes a new dimension: to what extent the alternatives are strategically relevant for future challenges. We conclude the chapter by pointing out interesting directions for future research, including a call for empirical studies of the conceptual model developed in this chapter.

P–764 Risks of oocyte donation for third-party donors: a systematic literature review

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
J Tassot ◽  
A D’Angelo
Keyword(s):  
Case Reports ◽  
Empirical Studies ◽  
Oocyte Donation ◽  
Third Party ◽  
Short Term ◽  
Oocyte Donor ◽  
Social Risks ◽  
Oocyte Donors ◽  
Psychological Risks

Abstract Study question What are the risks of oocyte donation? Which risks should be prioritised in policies aiming to improve the protection of third-party oocyte donors? Summary answer The risks for third-party oocyte donors are of a diverse nature, including physical risks, psychological risks, iatrogenic risks, and social risks. What is known already Oocyte donation involves ovarian stimulation and oocyte pick-up, which represent burdensome procedures for the donor. In a recent evaluation of the EU legislation on blood, tissue and cells, the European Commission highlighted that oocyte donors are currently not adequately protected. For effective oocyte donor protection measures to be developed and implemented, it is important to understand the risks that oocyte donors are exposed to. To date, there is no comprehensive overview of the existing knowledge on the physical and psychosocial risks of oocyte donation. Study design, size, duration A systematic literature review of the publications on PubMed, CINAHL, PsycINFO and the Notify Library was carried out. The search was conducted in May 2020. All empirical studies, including case reports, that reported or investigated negative experiences of oocyte donors and/or negative consequences of the donation on the donors’ physical health, mental health, or other aspects of their lives were included. No restriction was made with regard to the year of publication. Participants/materials, setting, methods In total, 88 empirical studies conducted in oocyte donors were reviewed. All reported information on oocyte donor risks was extracted and summarised. The identified risks were clustered into categories according to common themes and analysed with regard to their frequency of occurrence, severity, and imputability to the donation. A prioritisation of risks was carried out based on these three criteria, classifying each risk as a “priority risk” or a “non-priority risk”. Main results and the role of chance Nineteen priority risks were identified across the following six categories: short-term physical risks, long-term physical risks, short-term psychological risks, long-term psychological risks, iatrogenic risks, and social risks. The most frequently reported priority risks were moderate to severe Ovarian Hyperstimulation Syndrome (OHSS) and having lasting worries or concerns about the donation. While the findings confirmed the relevance of certain immediate physical risks for oocyte donors, no cases of death or permanent physical damage as a direct consequence of the donation could be detected. The results showed that donating oocytes can profoundly impact the donors’ psychological well-being in the short-term and in the long-term. Furthermore, the donation can have a strong effect on the donor’s social and family life, for instance, through the risk of unintended pregnancy. Moreover, it was found that oocyte donors are at risk of experiencing mistreatment or inadequate care during the donation procedure. Most studies included in the review reported on short-term risks of the donation. There is a high degree of uncertainty about the long-term health effects of oocyte donation. Due to the scarcity of large observational studies, the conclusions are mostly based on small studies and case reports, which limits the strength of any conclusion. Limitations, reasons for caution The literature search was limited to common databases for published data. Grey literature was not searched. Due to the heterogeneous nature of the relevant publications, it is possible that the search strategy was not able to detect all eligible articles. Wider implications of the findings: The findings emphasise the importance of implementing effective donor protection policies that address not only the physical, but also the psychological, social, and iatrogenic risks of oocyte donation. Moreover, the findings call for a systematic follow-up of oocyte donors to gain insight into the long-term consequences of the donation. Trial registration number Not applicable

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