928 resultados para Driver hypothesis
Resumo:
Self-Determination Theory (Deci and Ryan in Intrinsic motivation and self-determination in human behavior. Plenum Press, New York, 1985) suggests that certain experiences, such as competence, are equally beneficial to everyone’s well-being (universal hypothesis), whereas Motive Disposition Theory (McClelland in Human motivation. Scott, Foresman, Glenview, IL, 1985) predicts that some people, such as those with a high achievement motive, should benefit particularly from such experiences (matching hypothesis). Existing research on motives as moderators of the relationship between basic need satisfaction and positive outcomes supports both these seemingly inconsistent views. Focusing on the achievement motive, we sought to resolve this inconsistency by considering the specificity of the outcome variables. When predicting domain-specific well-being and flow, the achievement motive should interact with felt competence. However, when it comes to predicting general well-being and flow, felt competence should unfold its effects without being moderated by the achievement motive. Two studies confirmed these assumptions indicating that the universal and matching hypotheses are complementary rather than mutually exclusive.
Resumo:
The causes of the glacial cycle remain unknown, although the primary driver is changes in atmospheric CO(2), likely controlled by the biological pump and biogeochemical cycles. The two most important regions of the ocean for exchange of CO(2) with the atmosphere are the equatorial Pacific and the Southern Ocean ( SO), the former a net source and the latter a net sink under present conditions. The equatorial Pacific has been shown to be a Si(OH)(4)-limited ecosystem, a consequence of the low source Si(OH)(4) concentrations in upwelled water that has its origin in the SO. This teleconnection for nutrients between the two regions suggests an oscillatory relationship that may influence or control glacial cycles. Opal mass accumulation rate (MAR) data and delta(15)N measurements in equatorial cores are interpreted with predictions from a one- dimensional Si(OH)(4)-limited ecosystem model (CoSINE) for the equatorial Pacific. The results suggest that equatorial Pacific surface CO(2) processes are in opposite phase to that of the global atmosphere, providing a negative feedback to the glacial cycle. This negative feedback is implemented through the effect of the SO on the equatorial Si(OH)(4) supply. An alternative hypothesis, that the whole ocean becomes Si(OH)(4) poor during cooling periods, is suggested by low opal MAR in cores from both equatorial and Antarctic regions, perhaps as a result of low river input. terminations in this scenario would result from blooms of coccolithophorids triggered by low Si(OH)(4) concentrations.
Resumo:
This paper investigates empirically the Bolton, Scheinkman, and Xiong (2006) hypothesis, according to which initial shareholders may provide incentives to managers to take actions that stimulate speculative bubbles. We test this hypothesis with data on up to 8,544 directors and up to 1,677 companies between 2004-2008. Using vesting time as a measure of the short-term performance weighting in CEO compensation and various alternative measures of the extent of speculation, the findings support the hypothesis: vesting time decreases with more intensive speculation. The results prove robust in various empirical model specifications.
Resumo:
Enemy release is frequently posed as a main driver of invasiveness of alien species. However, an experimental multi-species test examining performance and herbivory of invasive alien, non-invasive alien and native plant species in the presence and absence of natural enemies is lacking. In a common garden experiment in Switzerland, we manipulated exposure of seven alien invasive, eight alien non-invasive and fourteen native species from six taxonomic groups to natural enemies (invertebrate herbivores), by applying a pesticide treatment under two different nutrient levels. We assessed biomass production, herbivore damage and the major herbivore taxa on plants. Across all species, plants gained significantly greater biomass under pesticide treatment. However, invasive, non-invasive and native species did not differ in their biomass response to pesticide treatment at either nutrient level. The proportion of leaves damaged on invasive species was significantly lower compared to native species, but not when compared to non-invasive species. However, the difference was lost when plant size was accounted for. There were no differences between invasive, non-invasive and native species in herbivore abundance. Our study offers little support for invertebrate herbivore release as a driver of plant invasiveness, but suggests that future enemy release studies should account for differences in plant size among species.
Resumo:
In the present article, we examine the hypothesis that high-school students' motivation to engage in cognitive endeavors (i.e., their need for cognition; NFC) is positively related to their dispositional self-control capacity. Furthermore, we test the prediction that the relation between NFC and school achievement is mediated by self-control capacity. A questionnaire study with grade ten high-school students (N = 604) revealed the expected relations between NFC, self-control capacity, and school achievement. Sobel tests showed that self-control capacity mediated the relation between NFC and school grades as well as grade retention.
Resumo:
A joint impact hypothesis on symptom experience is introduced that specifies the role of negative mood and self-focus, which have been considered independently in previous research. Accordingly, negative affect only promotes symptom experience when people simultaneously focus their attention on the self. One correlational study and 4 experiments supported this prediction: Only negative mood combined with self-focus facilitated the experience (see the self-reports in Studies 1, 2a, & 2b) and the accessibility (lexical decisions, Stroop task in Studies 3 & 4) of physical symptoms, whereas neither positive mood nor negative mood without self-focus did. Furthermore, the joint impact of negative mood and self-focused attention on momentary symptom experience remained significant after controlling for the influence of dispositional symptom reporting and neuroticism.
Resumo:
This study uses wage data from the UBS Prices and Earnings survey to highlight Disparate Wages in a Globalized World from di↵erent perspectives. This wage data is characterised by remarkable consistency over the last 40 years, as well as unusual global comparability. In the first chapter we analyse the convergence hypothesis for purchasing power adjusted wages across the world for 1970 to 2009. The results provide solid evidence for the hypotheses of absolute and conditional convergence in real wages, with the key driver being faster overall growing wage levels in lower wage countries compared to higher wage countries. At the same time, the highest skilled professions have experienced the highest wage growth, while low skilled workers’ wages have lagged, thus no convergence in this sense is found between skill groups. In the second chapter we examine deviations in international wages from Factor Price Equalisation theory (FPE). Following an approach analogous to Engel (1993) we find that deviations from FPE are more likely driven by the higher variability of wages between countries than by the variability of di↵erent wages within countries. With regard to the traditional analysis of the real exchange rate and the Balassa-Samuelson assumptions our analysis points to a larger impact on the real exchange rate likely stemming from the movements in the real exchange rate of tradables, and only to a lesser extent from the lack of equalisation of wages within countries. In the third chapter our results show that India’s economic and trade liberalisation, starting in the early 1990s, had very di↵erential impacts on skill premia, both over time and over skill levels. The most striking result is the large increase in wage inequality of high-skilled versus low-skilled professions. Both the synthetic control group method and the di↵erence-in-di↵erences (DID) approach suggest that a significant part of this increase in wage inequality can be attributed to India’s liberalisation.
Resumo:
Old captains at the helm: Chairman age and firm performance Urs Waelchli and Jonas Zeller December, 2012 This paper examines whether the chairmen of the board (COBs) impose their life-cycles on the firms over which they preside. Using a large sample of unlisted firms we find a robust negative relation between COB age and firm performance. COBs age much like ‘ordinary’ people. Their cognitive abilities deteriorate and they experience significant shifts in motivation. Deteriorating cognitive abilities are the main driver of the performance effect that we observe. The results imply that succession planning problems in unlisted firms are real. Mandatory retirement age clauses cannot solve these problems. Corporate Aging around the World Jonas Zeller January, 2014 This paper examines whether firms internationally age as US firms do (Loderer, Stulz, and Wälchli, 2013). Using a large panel, I find that Tobin’s Q monotonically falls with firm Age across all nineteen countries in the sample. The decrease varies across countries but is generally extremely robust and economically significant. ROA, sales growth, and market share decrease over a firm’s lifetime in most countries as well. Furthermore, older firms reduce their capital expenditures and R&D outlays. Instead, they distribute more cash to their shareholders. Overall, the results suggest that corporate aging is not confined to the US but is a genuine phenomenon that affects listed firms worldwide. This evidence supports the hypothesis that corporate aging is driven by managers who optimally focus on managing their assets in place and neglect the development of growth opportunities. I finally ask whether the managers’ choice and with it the magnitude of the decline in Tobin’s Q is a function of country-level institutional settings. I find that most notably firms age faster in countries where employees are relatively well protected by labor regulation. Is employment protection the fountain of corporate youth? Claudio Loderer, Urs Wälchli, Jonas Zeller* September 2014 Acharya, Baghai, and Subramanian (2012, 2013) find that employment protection legislation (EPL) encourages innovation. We argue that this effect should be particularly strong in mature firms. We would therefore also expect EPL to boost growth opportunities. Using the natural Experiment created by the staggered passage of changes in EPL across seventeen countries, we find evidence that employment protection legislation does indeed stimulate Innovation efforts, especially in mature firms. The effect is stronger in countries in which patents are owned by the firm and in the context of regular contracts. Consistent with that, EPL encourages risk taking. Overall, however, there is Little evidence that the effect of EPL on innovation effort translates into higher firm value, not even in mature firms. EPL does motivate employees in those firms to put in a greater effort, as evidenced by stronger sales growth. Yet it also increases costs, reduces profitability, and depresses Tobin’s Q ratios in all firms, especially the mature ones, possibly because of the rigidities that characterize these firms [Loderer, Stulz, and Waelchli (2014)].