Money demand and macroeconomic uncertainty

In this study we construct a measure of macroeconomic uncertainty from several observable economic indicators for the euro area. Indicator variables are based on financial market data, such as medium-term returns, loss and volatility measures but also come from surveys that capture business and consumer sentiment. From these we estimate the path of underlying macroeconomic uncertainty using an unobserved components model. Employing cointegration analysis it is demonstrated that the extracted measures of uncertainty help to explain the increase in euro area M3 over the period 2001 to 2004. Similar evidence can be found for US monetary aggregates. --Money demand,Macroeconomic Uncertainty,Excess Liquidity

Reliability models for dataflow computer systems

The demands for concurrent operation within a computer system and the representation of parallelism in programming languages have yielded a new form of program representation known as data flow (DENN 74, DENN 75, TREL 82a). A new model based on data flow principles for parallel computations and parallel computer systems is presented. Necessary conditions for liveness and deadlock freeness in data flow graphs are derived. The data flow graph is used as a model to represent asynchronous concurrent computer architectures including data flow computers

Estimating and Forecasting Aggregate Productivity Growth Trends in the US and Germany

This paper addresses the issue of estimating and forecasting productivity growth trends in the US and Germany from the perspective of a business cycle researcher who wants to use the available information in time series of aggregate labor productivity to derive a model for short- and/or long-term forecasts of labour productivity. We will use stability tests and a deterministic model with structural breaks that is estimated using the methods mentioned in Hansen (2001). The methodological approach also draws on Gordon (2003) using a Kalman filter specification. We discuss the implications of unit-root assumptions for long-term forecasts and argue in favor of a near unit-root modelling. That implies a convergence of productivity growth rates in both countries within the next 15 years.

A test for a conjecture on the nature of attractors for smooth dynamical systems

Dynamics arising persistently in smooth dynamical systems ranges from regular dynamics (periodic, quasiperiodic) to strongly chaotic dynamics (Anosov, uniformly hyperbolic, nonuniformly hyperbolic modelled by Young towers). The latter include many classical examples such as Lorenz and H\'enon-like attractors and enjoy strong statistical properties. It is natural to conjecture (or at least hope) that most dynamical systems fall into these two extreme situations. We describe a numerical test for such a conjecture/hope and apply this to the logistic map where the conjecture holds by a theorem of Lyubich, and to the Lorenz-96 system in 40 dimensions where there is no rigorous theory. The numerical outcome is almost identical for both (except for the amount of data required) and provides evidence for the validity of the conjecture.Comment: Accepted version. Minor modifications from previous versio

Prediction of power and energy use in dwellings : Addressing apects of thermal mass and occupant behaviour

Households are responsible for approximately 26 % of the annual energy use in the EU. Following the EU-directives regarding energy performance in buildings, international initiatives have been taken in Europe to help countries to define and include guidelines in their own building codes, for example, to establish the concept of zero energy buildings, ZEBs. This concept includes passive building energy-saving technologies, energy-efficient building services systems and renewable energy generation technologies. It is usually very difficult for a building to use zero energy and the concept has therefore been developed to include so-called net-zero energy buildings, or nearly zero energy buildings. These are usually defined as having a net-zero energy use on an annual basis and a nearly-zero energy use if they have a significantly lower use than stipulated in the respective national building codes. Technological advances have resulted in new buildings being very well insulated and, subsequently, using very little energy. However, the focus has now moved towards the use of renewable energy rather than only looking at the amount of energy used. Energy production can be achieved via numerous different arrangements and can be utilized in ways that are dependent on the time of day and the weather. Taking these different aspects into consideration, it can be assumed that the temporal variations regarding production can vary significantly. The heating demand of a building depends on the outdoor climate and the occupants’ behaviour, which leads to an uncertain situation with regard to matching the renewable production and demand, and even more so when the occupants’ behaviour is subject to temporal variations. In addition to the temporal variations, occupant actions or preferences are subject to large stochastic variations within a population. Thus, when designing to meet these challenges, the temporal resolution would have to be higher with regard not only to demand but also to the renewable energy production, in order to provide general benefits as well as covering a larger part of the possible future scenarios.This thesis aims show how the use of household electricity and domestic hot water varies and how these variations impact the energy and power demand of buildings. Additionally, in order to achieve a higher possible level of load matching there is a need to time shift power loads. This is another building operation process that has been investigated. The primary method in both cases has been to use building simulations with large amounts of measurement data for occupant behaviour as input to the simulation models. By randomly inserting different measurement data sets, and running simulations repeatedly, the outcomes were hundreds of annual energy and power demands that varied with the variation of the input.Furthermore, load shifting was investigated by abruptly reducing the heating power supply to buildings. The heat stored in the building envelope and furniture was then used to reduce the effects on the indoor temperature. This thesis examines the temperature drops caused by such power reductions and the various factors that affect the size of the temperature drops, such as the thermal mass and the properties of the building envelope, as well as the stochastic behaviour of the occupants that creates the internal heat load

Periodic behaviour of coronal mass ejections, eruptive events, and solar activity proxies during solar cycles 23 and 24

We report on the parallel analysis of the periodic behaviour of coronal mass ejections (CMEs) based on 21 years [1996 -- 2016] of observations with the SOHO/LASCO--C2 coronagraph, solar flares, prominences, and several proxies of solar activity. We consider values of the rates globally and whenever possible, distinguish solar hemispheres and solar cycles 23 and 24. Periodicities are investigated using both frequency (periodogram) and time-frequency (wavelet) analysis. We find that these different processes, in addition to following the $\approx$11-year Solar Cycle, exhibit diverse statistically significant oscillations with properties common to all solar, coronal, and heliospheric processes: variable periodicity, intermittence, asymmetric development in the northern and southern solar hemispheres, and largest amplitudes during the maximum phase of solar cycles, being more pronounced during solar cycle 23 than the weaker cycle 24. However, our analysis reveals an extremely complex and diverse situation. For instance, there exists very limited commonality for periods of less than one year. The few exceptions are the periods of 3.1--3.2 months found in the global occurrence rates of CMEs and in the sunspot area (SSA) and those of 5.9--6.1 months found in the northern hemisphere. Mid-range periods of $\approx$1 and $\approx$2 years are more wide spread among the studied processes, but exhibit a very distinct behaviour with the first one being present only in the northern hemisphere and the second one only in the southern hemisphere. These periodic behaviours likely results from the complexity of the underlying physical processes, prominently the emergence of magnetic flux.Comment: 33 pages, 15 figures, 2 table

Calculating potential growth rates and output gaps - A revised production function approach

Any meaningful analysis of cyclical developments, of medium term growth prospects or of the stance of fiscal and monetary policies are all predicated on either an implicit or explicit assumption concerning the rate of potential output growth. Given the importance of the concept, the measurement of potential output is the subject of contentious and sustained research interest. All the available methods have "pros" and "cons" and none can unequivocally be declared better than the alternatives in all cases. Thus, what matters is to have a method adapted to the problem under analysis, with well defined limits and, in international comparisons, one that deals identically with all countries. This is the approach adopted in the present paper where it is stated clearly that the objective is to produce an economics based, production function, method which can be used for operational EU policy surveillance purposes.growth rates, cyclical developments, production function, potential output, Denis, Grenouilleau, Mc Morrow, R�ger