Growth and volatility regime switching models for New Zealand GDP data

This paper fits hidden Markov switching models to New Zealand GDP data. A primary objective is to better understand the utility of these methods for modelling growth and volatility regimes present in the New Zealand data and their interaction. Properties of the models are developed together with a description of the estimation methods, including use of the Expectation Maximisation (EM) algorithm. The models are fitted to New Zealand GDP and production sector growth rates to analyse changes in their mean and volatility over time. The paper discusses applications of the methodology to identifying changes in growth performances, and examines the timing of growth and volatility regime switching between production sectors. Conclusions to emerge are that, in contrast to the 1980s, New Zealand GDP growth experienced an unusually long period of time in high growth and low volatility regimes during the 1990s. The paper evaluates sector contributions to this 1990s experience and discusses directions for further development.Hidden Markov models; regime switching; growth; business cycles; volatility; production sectors; GDP.

Calm after the Storm?: Supply-side contributions to New Zealand’s GDP volatility decline

The variance of New Zealand’s real GDP has declined since the mid-1980s. To investigate why, this paper decomposes the variance of chain-weighted estimates of production-based real GDP growth into sector shares, sector growth rate variances and co-variances. The principal explanation for the decline in GDP volatility is a fall in the sum of sector variances driven by a decline in the Services and Manufacturing sector production growth variances. Sector co-variances have had a dominant influence on the profile of GDP volatility and this influence has not diminished. Despite marked changes in sector shares, notably increases in Services and Primary sector shares and a decrease in the share of Manufacturing, this has not been a significant factor influencing the decline in GDP volatility. We postulate that policy interventions such as “Think Big”, regulatory interventions during the early 1980s, and the introduction of GST are key explanations for the higher volatility until the mid 1980s. Cessation of these interventions, deregulation and possibly changes in inventory management methods are important reasons why GDP volatility has fallen since then.Volatility, growth, production sector shares, manufacturing, services, primary, construction.

Toward a Model of Firm Productivity Dynamics

A common finding from international research on firm productivity dynamics is that withinfirm productivity dynamics tend to dominate the effects of firm entry and exit on aggregate productivity. The aim of this paper is to explore the suitability of Statistics New Zealand’s Business Demography (BD) and Goods and Services Tax (GST) data as a basis for modelling within-firm productivity dynamics. The paper first analyses and describes the cross-sectional and time-series properties of sales, purchases and a value-added measure of labour productivity. Cross-sectional results reveal a great deal of heterogeneity in average sales, purchases and labour productivity both across and within industries and cohorts. Univariate time-series properties of these variables are remarkably similar and sales and purchases are highly correlated contemporaneously. Transition probabilities are also calculated for movement of firms between quartiles of the labour productivity distribution over varying lengths of time. In order to understand the processes driving the data, a simple statistical model for sales, purchases and value-added per unit of employment is developed to calibrate to the stylised empirical facts. The model does a remarkably good job at mimicking the properties of the BD and GST data.Firm Productivity; Labour Productivity; Firm Dynamics; New Zealand GST Data; New Zealand Business Demography; Firm Value-added.

Tentative Evidence for Relativistic Electrons Generated by the Jet of the Young Sun-like Star DG Tau

Synchrotron emission has recently been detected in the jet of a massive protostar, providing further evidence that certain jet formation characteristics for young stars are similar to those found for highly relativistic jets from AGN. We present data at 325 and 610 MHz taken with the GMRT of the young, low-mass star DG Tau, an analog of the Sun soon after its birth. This is the first investigation of a low-mass YSO at at such low frequencies. We detect emission with a synchrotron spectral index in the proximity of the DG Tau jet and interpret this emission as a prominent bow shock associated with this outflow. This result provides tentative evidence for the acceleration of particles to relativistic energies due to the shock impact of this otherwise very low-power jet against the ambient medium. We calculate the equipartition magnetic field strength (0.11 mG) and particle energy (4x10^40 erg), which are the minimum requirements to account for the synchrotron emission of the DG Tau bow shock. These results suggest the possibility of low energy cosmic rays being generated by young Sun-like stars.Comment: 19 pages, 2 figures, accepted for publication in ApJ Letter

Team 3: Exploring the relationship of systems research to systems literacy

In this paper, the Systems Research Team (SRT) details the activities and outcomes of the 2016 IFSR Conversation in Linz, Austria. The 2016 SRT includes: Mary Edson (team leader), Pam Buckle Henning, Tim Ferris, Andreas Hieronymi, Ray Ison, Gary Metcalf, George Mobus, Nam Nguyen, David Rousseau, and Shankar Sankaran, with guest team member, Peter Tuddenham, anchoring the endeavor in Systems Literacy. While the 2014 SRT’s focus was answering the question, “What distinguishes Systems Research from other types of research?” an internal focus intended to provide grounding for researchers new to the Systems Sciences, the 2016 SRT’s focus is on reaching out to a broader community in order to provide a foundation for Systems Literacy. The team’s Conversation revolved around the question, “How can Systems Research be in service to Systems Literacy?” The team’s discussions were directed into two essential aspects, separate and integrated, of this question. First, Systems Research serves Systems Literacy by providing a credible foundation for the principles and practices of Systems Science and Systems Thinking in both systematic and systemic modes. Second, Systems Research provides a neutral frame for development of ethical applications of those principles and practices. The SRT recognizes the exigency in providing foundational principles that can be effectively adopted and disseminated through Systems Literacy. The team’s narrative begins with an understanding the urgency for application of Systems Sciences and Systems Thinking to critical issues. Systems research, as with other types of research, is typically a slow generation of results; however, the body of knowledge gained through this process can be confidently used to address complexity in timely ways. The criticality of the need for salient approaches to complexity is shown in a graphic representation of some possible trajectories of applying or not applying these Systems principles in practice. The choice of how we respond to these issues relates to a process model that can be applied. Through understanding the relationship of the process model to the trajectory, the team directed its focus to developing a MindMap (Eppler, 2006) of eight essential aspects or features of how Systems Research can support Systems Literacy. These include: Systems Science knowledge base, roles and personas, maturity models, role profile, ontology/vocabulary, perspective/framing choice, frameworks, and political ecology. Each of these eight has its own process of unpacking, which was demonstrated to the Conversation participants by delving more deeply into the aspect of knowledge base. The eight relate to unpacking the Systems landscape in a coherent but loosely coupled investment portfolio (economic, social, and relational) for building systemic sensibility in such a way as to be dis/aggregated for different audiences. The week’s work culminated in a plan for “Looking Ahead,” which outlines the intentions of the SRT to continue its activities in support of Systems Literacy in the upcoming months. An example of this continued work is a workshop, “Toward Systems Literacy, the Role of Systems Research,” that was conducted at the 60th Meeting of the International Society for the Systems Sciences in Boulder, July 25, 2016

Radio continuum observations of Class I protostellar disks in Taurus: constraining the greybody tail at centimetre wavelengths

We present deep 1.8 cm (16 GHz) radio continuum imaging of seven young stellar objects in the Taurus molecular cloud. These objects have previously been extensively studied in the sub-mm to NIR range and their SEDs modelled to provide reliable physical and geometrical parametres.We use this new data to constrain the properties of the long-wavelength tail of the greybody spectrum, which is expected to be dominated by emission from large dust grains in the protostellar disk. We find spectra consistent with the opacity indices expected for such a population, with an average opacity index of beta = 0.26+/-0.22 indicating grain growth within the disks. We use spectra fitted jointly to radio and sub-mm data to separate the contributions from thermal dust and radio emission at 1.8 cm and derive disk masses directly from the cm-wave dust contribution. We find that disk masses derived from these flux densities under assumptions consistent with the literature are systematically higher than those calculated from sub-mm data, and meet the criteria for giant planet formation in a number of cases.Comment: submitted MNRA

A qualitative analysis of the effectiveness of telehealthcare devices (i) are they meeting the needs of end-users?

Background: There are many telehealthcare devices currently available ranging from personal alarms, automated pill dispensers and fall detectors through to monitoring devices for blood sugar, blood pressure and heart rate. Many devices remain unused once acquired or shortly after a period of initial use. Methods: The study used a qualitative design involving focus groups and interviews. End users’ opinions of telehealthcare devices were examined through focus groups along with the views of market experts and key supply chain players through telephone interviews to ascertain their views on the devices. The data were recorded, transcribed and analysed thematically. Results: Amongst the wide range of user issues associated with telehealthcare devices two themes merited particular attention: design characteristics and the lack of focus on end-user needs. Our findings suggested that few telehealthcare devices appear to be developed based on the principles of user-centred design. Consequently, many were non-intuitive to use, with the majority of the focus group participants not recognising the purpose of the devices from their appearance alone. Conclusions: Greater input from real end-users rather than “proxy” users such as carers, professional users or technologists is required when developing telehealthcare devices or systems. Design should be focussed on intuitive use to enable the user to successfully achieve what is required from the devices. This may require the existing supplier—driven market focus to be challenged, but could improve the contribution of technology to improving healthcare

Learning in the Palaver Hut: The ‘Africa Study Visit’ as teaching tool.

noThe aim of this article is to assess the experiential learning environment of the African Study Visit (ASV). It presents a theoretically grounded analysis of the ASV. Although field visits are not a new phenomenon within Higher Education, they seem, but with few exceptions, to be considered as an add-on teaching method. By drawing from the experiential learning literature, we demonstrate that there are sound pedagogical reasons for incorporating field visits like the ASV into the curriculum as stand-alone components. Thus, the original contribution of this article is to place the ASV within the experiential learning literature such that the theoretical, practical and conceptual benefits for students are understood. Its significance is that this article offers a set of practices from an experiential learning perspective that can be used for deepening the levels of comprehension of political issues in Africa for international studies students