Price elasticity of electricity demand: Using instrumental variable regressions to address endogeneity and autocorrelation of high-frequency time series

This paper examines empirical methods for estimating the response of aggregated electricity demand to high-frequency price signals, the short-term elasticity of electricity demand. We investigate how the endogeneity of prices and the autocorrelation of the time series, which are particularly pronounced at hourly granularity, affect and distort common estimators. After developing a controlled test environment with synthetic data that replicate key statistical properties of electricity demand, we show that not only the ordinary least square (OLS) estimator is inconsistent (due to simultaneity), but so is a regular instrumental variable (IV) regression (due to autocorrelation). Using wind as an instrument, as it is commonly done, may result in an estimate of the demand elasticity that is inflated by an order of magnitude. We visualize the reason for the Thams bias using causal graphs and show that its magnitude depends on the autocorrelation of both the instrument, and the dependent variable. We further incorporate and adapt two extensions of the IV estimation, conditional IV and nuisance IV, which have recently been proposed by Thams et al. (2022). We show that these extensions can identify the true short-term elasticity in a synthetic setting and are thus particularly promising for future empirical research in this field.Comment: 25 pages, 12 figures, 2 table

Cost-Potential Curves of Onshore Wind Energy: the Role of Disamenity Costs

Numerical optimization models are used to develop scenarios of the future energy system. Usually, they optimize the energy mix subject to engineering costs such as equipment and fuel. For onshore wind energy, some of these models use cost-potential curves that indicate how much electricity can be generated at what cost. These curves are upward sloping mainly because windy sites are occupied first and further expanding wind energy means deploying less favorable resources. Meanwhile, real-world wind energy expansion is curbed by local resistance, regulatory constraints, and legal challenges. This presumably reflects the perceived adverse effect that onshore wind energy has on the local human population, as well as other negative external effects. These disamenity costs are at the core of this paper. We provide a comprehensive and consistent set of cost-potential curves of wind energy for all European countries that include disamenity costs, and which can be used in energy system modeling. We combine existing valuation of disamenity costs from the literature that describe the costs as a function of the distance between turbine and households with gridded population data, granular geospatial data of wind speeds, and additional land-use constraints to calculate such curves. We find that disamenity costs are not a game changer: for most countries and assumptions, the marginal levelized cost of onshore wind energy increase by 0.2-12.5 euro/MWh.ISSN:0924-6460ISSN:1573-150

Patients' direction, empowerment and quality of life in haemodialysis

The maintenance of an adequate of quality of life (QoL) represents a critical issue in the management of patients in haemodialysis and is also used to assess the effectiveness of health care programmes. The Consumer Direction Theory of Empowerment (CDTE) implies that greater patient direction in policy formulation and services delivery, together with an increased community integration, endorses a process which leads to a better QOL. The aim of the study was to test a contextualized version of CDTE in an ambulatory for patients in haemodialysis. Sixty-nine patients completed a questionnaire measuring the following variables: Patient direction, family integration, self-efficacy in managing the disease, mental and physical health. The results showed that patient direction and family integration have an indirect effect on QoL, through self-efficacy in managing the disease. The hypotheses were thus confirmed, providing support for the potential of CDTE in the context of health services for haemodialysis patients. Implications for the implementation of health programmes aimed at improving QoL of patients in haemodialysis are discussed, including interventions focused on psychological and contextual factors