A Schumpeterian Growth Model with Heterogenous Firms

A common assumption in the Schumpeterian growth literature is that the innovation size is constant and identical across industries. This is in contrast with the empirical evidence which shows that: (i) the innovation size is far from being identical across industries; and (ii) the size distribution of profit returns from innovation is highly skewed toward the low value side, with a long tail on the high value side. In the present paper, we develop a Schumpeterian growth model that is consistent with this evidence. In particular, we assume that when a firm innovates, the size of its quality improvement is the result of a random draw from a Pareto distribution. This enables us to extend the class of quality-ladder growth models to encompass firm heterogeneity. We study the policy implications of this new set-up numerically and find that it is optimal to heavily subsidize R&D for plausible parameter values. Although it is optimal to tax R&D for some parameter values, this case only occurs when the steady-state rate of economic growth is very low.Schumpeterian Growth, R&D, optimal policy

Ovarian hormones and borderline personality disorder features: Preliminary evidence for interactive effects of estradiol and progesterone

Cyclical fluctuations in the ovarian hormones 17β-estradiol (E2; estrogen) and progesterone (P4) predict emotions, cognitive processes, and behaviors relevant to Borderline Personality Disorder (BPD); however, there are individual differences in sensitivity to normal hormone shifts. This study examined associations of naturally occurring hormonal changes with concurrent BPD feature expression. Forty women sampled for a flat distribution of the PAI-BOR (n=10 where T70) provided 4 weekly saliva samples and psychological assessments. Across most outcomes (e.g., BPD features, felt rejection, anger rumination, negative urgency) P4 deviation (from one’s person mean) moderated the effect of current E2 deviation (from one’s person mean) among women high (+1 SD) in trait BPD features such that E2 deviation was negatively associated with symptoms only when P4 was higher-than-usual. Cyclical hormone changes (e.g., higher P4 in the luteal phase; E2 fluctuations at ovulation and in the luteal phase) may impact BPD feature expression among at-risk women

Facts and distortions in an endogenous growth model with physical capital, human capital and varieties

This article studies a model with physical and human capital accumulation and varieties. The model includes several distortions: duplication effects, spillovers, creative destruction, surplus appropriability, and an erosion effect. We show that the duplication effect in R&D is essential to make the model replicate several stylized facts linked with R&D. We evaluate the distance to the optimal solution, comparing the strength of each distortion.info:eu-repo/semantics/publishedVersio

Dispositional optimism as a correlate of decision-making styles in adolescence

Despite the numerous psychological areas in which optimism has been studied, including career planning, only a small amount of research has been done to investigate the relationship between optimism and decision-making styles. Consequently, we have investigated the role of dispositional optimism as a correlate of different decision-making styles, in particular, positive for effective styles and negative for ineffective ones (doubtfulness, procrastination, and delegation). Data were gathered through questionnaires administered to 803 Italian adolescents in their last 2 years of high schools with different fields of study, each at the beginning stages of planning for their professional future. A paper questionnaire was completed containing measures of dispositional optimism and career-related decision styles, during a vocational guidance intervention conducted at school. Data were analyzed using stepwise multiple regression. Results supported the proposed model by showing optimism to be a strong correlate of decision-making styles, thereby offering important intervention guidelines aimed at modifying unrealistically negative expectations regarding their future and helping students learn adaptive decision-making skills

The SNAPSHOT study protocol : SNAcking, Physical activity, Self-regulation, and Heart rate Over Time

Peer reviewedPublisher PD

Why do People Worry and Ruminate? Investigating Factors that Maintain Repetitive Negative Thought

The overarching aim of this research was to understand factors implicated in the maintenance of rumination and worry, conceptualised as a transdiagnostic process of repetitive negative thought (RNT), through the use of cross-sectional, prospective, and experimental research designs. Rumination and worry have been repeatedly implicated in the development and maintenance of various forms of psychopathology, in particular, depression and anxiety disorders. Given the negative outcomes for mood and psychopathology, there is a need for a better understanding of vulnerability factors that maintain this unconstructive thinking. Based on a review of the literature, an integrative theoretical model was developed and tested using structural equation modelling. Using cross-sectional data, the model was tested in a large sample of adults (n = 506). Of the broad range of proximal and distal vulnerability factors examined, only neuroticism and beliefs about the function of repetitive thought remained significantly associated with RNT once current symptoms were statistically controlled. Emotional abuse and abstract processing were indirectly associated with RNT. Following on from this, a prospective study examined which of these vulnerability factors prospectively predicted change in RNT over six to eight weeks. Only neuroticism and the specific belief that repetitive thought aids instrumental understanding predicted change in RNT, after controlling for depression and anxiety symptoms. Next, two experimental studies were conducted to explore the causal relationship between RNT and the belief that RNT aids insight and understanding, by experimentally manipulating this appraisal and measuring the impact on state RNT. Whilst methodological issues with the first experimental study precluded clear conclusions being drawn about the nature of the relationship, the second experimental study demonstrated that participants manipulated to believe that RNT is helpful for increasing insight and understanding had greater levels of state RNT after exposure to a stressor, relative to participants manipulated to believe that RNT is unhelpful. Finally, in order to see whether rumination has any consequences that may potentially reinforce its further use, an experimental study was conducted to manipulate processing mode (abstract rumination versus concrete thinking) and examine the effect on a range of outcomes relating to insightfulness and avoidance. Whilst rumination did not lead to increased insight, it did afford more justification for avoidance, relative to concrete thinking. The clinical and theoretical implications of these findings are discussed with respect to existing theories of repetitive negative thought

The Role of Rumination and Reduced Concreteness in the Maintenance of Posttraumatic Stress Disorder and Depression Following Trauma

Rumination has been linked to posttraumatic stress disorder (PTSD) and depression following trauma. A cross-sectional (N = 101) and a prospective longitudinal study (N = 147) of road traffic accident survivors assessed rumination, PTSD and depression with self-report measures and structured interviews. We tested the hypotheses that (1) rumination predicts the maintenance of PTSD and depression and (2) reduced concreteness of ruminative thinking may be a maintaining factor. Rumination significantly predicted PTSD and depression at 6 months over and above what could be predicted from initial symptom levels. In contrast to the second hypothesis, reduced concreteness in an iterative rumination task was not significantly correlated with self-reported rumination frequency, and did not consistently correlate with symptom severity measures. However, multiple regression analyses showed that the combination of reduced concreteness and self-reported frequency of rumination predicted subsequent PTSD better than rumination frequency alone. The results support the view that rumination is an important maintaining factor of trauma-related emotional disorders

Discourse, affect and affliction

While much recent theorizing into affect has challenged the primacy of discourse in understanding social life, this paper is premised on the intertwining of affective experience with discursive meaning. Furthermore, appreciating the entwining of affect and discourse facilitates broader understanding into the illness experience, medical decision-making and experiences of healing. Today, the biomedical discourse carries particular affective weight that can saturate experiences of affliction. Cultural understandings of disease similarly shape affect that may emerge in affliction. Social meaning, more specifically stereotypes pertaining to identities, interweave with emotion also in the context of medical practice. The doctor-patient relationship is an affect-laden encounter where the entwining of affect with social assumptions carries important, yet poorly understood, repercussions for treatment decisions and for the furthering of health inequalities. Both the elusiveness and the power of affect that unfolds in relation to discursive meaning rest on the way in which affect dwells in and resounds through the body

Optimism/pessimism and health-related quality of life during pregnancy across three continents: a matched cohort study in China, Ghana, and the United States

<p>Abstract</p> <p>Background</p> <p>Little is known about how optimism/pessimism and health-related quality of life compare across cultures.</p> <p>Methods</p> <p>Three samples of pregnant women in their final trimester were recruited from China, Ghana, and the United States (U.S.). Participants completed a survey that included the Life Orientation Test - Revised (LOT-R, an optimism/pessimism measure), the Short Form 12 (SF-12, a quality of life measure), and questions addressing health and demographic factors. A three-country set was created for analysis by matching women on age, gestational age at enrollment, and number of previous pregnancies. Anovas with post-hoc pairwise comparisons were used to compare results across the cohorts. Multivariate regression analysis was used to create a model to identify those variables most strongly associated with optimism/pessimism.</p> <p>Results</p> <p>LOT-R scores varied significantly across cultures in these samples, with Ghanaian pregnant women being the most optimistic and least pessimistic and Chinese pregnant women being the least optimistic overall and the least pessimistic in subscale analysis. Four key variables predicted approximately 20% of the variance in overall optimism scores: country of origin (p = .006), working for money (p = .05); level of education (p = .002), and ever being treated for emotional issues with medication (p < .001). Quality of life scores also varied by country in these samples, with the most pronounced difference occurring in the vitality measure. U.S. pregnant women reported far lower vitality scores than both Chinese and Ghanaian pregnant women in our sample.</p> <p>Conclusion</p> <p>This research raises important questions regarding what it is about country of origin that so strongly influences optimism/pessimism among pregnant women. Further research is warranted exploring underlying conceptualization of optimism/pessimism and health related quality of life across countries.</p