Inflation, Investment Composition and Total Factor Productivity

This paper employs a dynamic stochastic general equilibrium model with a financial market friction to rationalize the empirically observed negative relationship between inflation and total factor productivity (TFP). Specifically, an empirical analysis of US macroeconomic time series establishes that there is a negative causal effect of inflation on aggregate productivity. Rather than taking the productivity process as exogenous, the model is therefore set up to feature an endogenous component of TFP. This is achieved by allowing physical investment to be channelled into two distinct technologies: a safe, but return-dominated technology and a superior technology which is subject to idiosyncratic liquidity risk. An agency problem prevents complete insurance against liquidity risk, and the scope for insurance is endogenously determined via the relevant liquidity premium. Since the liquidity premium is positively related to the rate of inflation, the model demonstrates how nominal fluctuations have an influence not only on the overall amount, but also on the qualitative composition of aggregate investment and hence on TFP. The quantitative relevance of the underlying transmission mechanism which links nominal fluctuations to TFP via corporate liquidity holdings and the composition of aggregate investment is corroborated by means of the quantitative analysis of the calibrated model economy as well as a detailed analysis of industry-level and firm-level panel data. Notably, the empirical findings are consistent with both the properties of the agency problem postulated in the theoretical model and its implications for corporate liquidity holdings and physical investment portfolios.

Review of botulinum toxin type A for the prophylactic treatment of chronic daily headache

Botulinum toxin A is increasingly used in the treatment of idiopathic and symptomatic headache disorders. However, only few controlled trials are available and many trials can hardly be compared to each other because of different endpoints and different trial designs. In particular chronic daily headache, which is defined as an idiopathic headache occurring on more than 15 days per month for at least 3 months and a daily duration of at least 4 hours, is considered as a headache disorder with possible efficacy of botulinum toxin A. For the prophylactic treatment of chronic tension-type headache and chronic migraine, no sufficient positive evidence for a successful treatment can be obtained from randomized, double-blind, and placebo-controlled trials to date. For the treatment of chronic daily headache including medication overuse headache, there is some positive evidence for efficacy in a subgroup of patients. To date, the majority of double-blind and placebo-controlled studies do not suggest that botulinum toxin A is efficacious in the treatment of chronic idiopathic headache disorders. However, it is possible that some subgroups of patients with chronic daily headache will benefit from a long-term treatment with botulinum toxin A

Inflation, Liquidity Risk and Long-run TFP - Growth

This paper demonstrates a negative relation between inflation and long-run productivity growth. Inflation generates long-run real effects due to a link from the short-run nominal and financial frictions to a firm's qualitative investment portfolio. We develop an endogenous growth model whose key ingredients are (i) a nominal short-run portfolio choice for households, (ii) an agency problem which gives rise to financial market incompleteness, (iii) a firm-level technology choice between a return-dominated but secure and a more productive but risky project. In this framework, inflation increases the costs of corporate insurance against productive but risky projects and hence a firm's choice of technology. It follows that each level of inflation is associated with a different long-run balanced growth path for the economy as long as financial markets are incomplete. Finally, we apply U.S. industry and firm level data to examine the relevance of our specific microeconomic mechanism. We find that (i) firms insure systematically against risky R&D investments by means of corporate liquidity holdings, (ii) periods of higher inflation restrain firm-level R&D investments by reducing corporate liquidity holdings.

Inflation, liquidity and innovation

This paper presents a simple model with financial frictions where inflation increases the cost faced by firms holding liquid assets to hedge risky production against expenditure shocks. Inflation tilts firms' technology choice away from innovative activities and toward safer but return-dominated ones, and therefore reduces long-run growth. The theory makes specific predictions about how the severity of this adverse effect depends on industry characteristics. These predictions are tested with novel harmonized firm-level data from 139 developing countries, overcoming small sample problems constraining previous work. The analysis finds that inflation affects the composition but not the overall quantity of investment. A one percentage point increase in inflation reduces the establishment-level probability of innovation by 4.3 percent but does not affect total investment. Moreover, innovating firms display a stronger dependence on liquid assets, which, in turn, are negatively related to inflation. Generalized difference-in-differences estimations corroborate the sector-specific predictions of the theoretical model

VENUS meets SEMAT : How do they compare?

SEMAT (Software Engineering Methods And Theory) is an initiative to define a generic foundation for software engineering as a rigorous discipline. The so-called SEMAT kernel provides a thinking framework for software engineers that is not constrained to certain methods and processes but aims to encompass all kinds of proven principles and best practices. Our own interdisciplinary VENUS development method is designed to achieve similar generality and compatibility objectives, although the chosen application domain in VENUS has a much narrower scope. In this paper we compare the VENUS development method with SEMAT. The main contributions are positioning the VENUS development concepts within the SEMAT conceptual framework, and investigating whether SEMAT is an appropriate framework for dealing with inherently interdisciplinary development processes. In the end we present suggestions for the improvement of both approaches.Sociedad Argentina de Informática e Investigación Operativa (SADIO

VENUS meets SEMAT : How do they compare?

SEMAT (Software Engineering Methods And Theory) is an initiative to define a generic foundation for software engineering as a rigorous discipline. The so-called SEMAT kernel provides a thinking framework for software engineers that is not constrained to certain methods and processes but aims to encompass all kinds of proven principles and best practices. Our own interdisciplinary VENUS development method is designed to achieve similar generality and compatibility objectives, although the chosen application domain in VENUS has a much narrower scope. In this paper we compare the VENUS development method with SEMAT. The main contributions are positioning the VENUS development concepts within the SEMAT conceptual framework, and investigating whether SEMAT is an appropriate framework for dealing with inherently interdisciplinary development processes. In the end we present suggestions for the improvement of both approaches.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Combining forces. Distributed Leadership and a professional learning community in primary and secondary education

This report describes an in depth case study of two good practice schools where a professional learning community and distributed leadership are highly developed. The goal of this study was to learn what conditions in the school support a professional learning community and distributed leadership. We gave specific attention to the supporting role of the school leader. The importance of continuous school improvement is self-evident and is achieved when teachers and school leaders collaboratively address educational issues, also known as a professional learning community (PLC). Within a PLC, school leaders and teachers alike must have the opportunity to take influence. Leadership is therefore not only exercised by the school leader, but is based on expertise, talents and qualities that are necessary for the issues at hand. This is known as distributed leadership (DL). A PLC and DL are combining forces, the sum of both drives the process of school improvement. However, as a previous study shows, teachers and school leaders still often struggle to collaborate and to make use of each other’s expertise. After an elaborate selection process - through an online survey and group interviews - two schools in The Netherlands were identified as good practices of a PLC and DL. The selected good practices are: primary school ‘Willibrordus’ and secondary school ‘Vathorst College’. We visited these schools and spoke with and observed teachers and school leaders. In the good practice schools, school leaders combine an informal role to support DL and a PLC and formal tools to necessitate and enable it. Most strikingly is that at Willibrordus and Vathorst the daily work- and educational practices are organised to enable and entice teachers to work together on school improvement and innovation. It seems that these collaborative practices - that are absent in most schools - are what lay the base for DL and a PLC. However, these practices are not sufficient. Additionally, within such a practice teachers and school leaders alike must show or develop the ability to professionally communicate with each other. At Vathorst College and Willibrordus this professional conversation entails giving constructive feedback, communicating openly and approaching the other respectfully. Other highlights from these descriptions are the following. Willibrordus and Vathorst College show a culture that is characterised by a large amount of teacher autonomy, creativity and cooperation between teachers. Both schools lay a strong emphasis on professional development (formally organised and informally supported) that helps teachers to gain new ideas and take influence from their acquired expertise. Finally, in both schools school leaders and teachers hold clear professional expectations of each other. In addition to the insight in the practice of two schools, this study concludes with the following recommendations for school leaders and teachers to stimulate a PLC and DL in their school: • Create practices that make collaboration inevitable. • Communicate through a professional dialogue. • Make radical decisions about the educational practice in line with the school’s vision. • Discuss what it means to be a professional at your school

Change in intraindividual ICHD-II headache diagnosis over time: A follow-up of the DMKG headache study

Background: Change in headache diagnoses over time within the same individual is not well studied in the adult population. In this study, we prospectively examined the individual variation of migraine and tension-type headache (TTH) diagnoses over time. Methods: As part of the epidemiological Deutsche Migrane und Kopfschmerzgesellschaft (DMKG) headache study, 1312 participants were personally interviewed and 1122 responded to a second mailed questionnaire 2.2 years later. Headaches were assigned to migraine or TTH at two different points in time using the International Headache Classification, ICHD-II. We used broad (definite and probable subtypes) and strict (only definite type) definitions of migraine and TTH. Results: Using the broad definition increased the reproducibility of migraine diagnosis from 48.0% to 62.0% and of TTH from 59.0% to 65.0%. A constant TTH diagnosis was related to a higher social status (OR 2.81; 95% CI 1.43-5.53) a higher level of education (OR 1.96; 95% CI 1.00-3.85) and physical inactivity (OR 2.28; 95% CI 1.16-4.49). A constant diagnosis of definite migraine was associated with severe headache (OR 2.64; 95% CI 0.97-7.21) and frequent use of headache medication (OR 4.73; 95% CI 0.95-23.60). The result that coexisting TTH decreased the likelihood of a constant migraine (OR 0.29; 95% CI 0.10-0.85) is assumed to indicate response variability. Conclusions: In epidemiological studies, definite and probable subtypes should be included in the diagnosis to increase the diagnostic accuracy

PSDefoPAT—Persistent Scatterer Deformation Pattern Analysis Tool

Persistent Scatterer Deformation Pattern Analysis Tool, for short PSDefoPAT, was designed to assign each measuring point of an advanced DInSAR data set a best-fitting time series model based on its displacement time series. In this paper, we will outline the operating principles of the tool. The periodic and trend components of a time series model are separately determined based on hypothesis tests. The periodic component is fitted as a sine function, and for the trend component, linear, quadratic, and piecewise linear regression models are considered. Additionally, the tool assesses the goodness-of-fit for each model in the form of the adjusted coefficient of determination $R^2_{adj}$ value. The tool works fully automatically and thus facilitates the analysis of large data sets, which are becoming more available to the public due to services such as the European Ground Motion Service. Additionally, we demonstrate the capabilities of PSDefoPAT using four case studies characterized by different deformation mechanisms, various extents of active deformation area, and varying density of measuring points. In all cases, we successfully reveal information on the temporal behavior of the deformation not apparent in the typically presented mean deformation velocity maps