Coupling techno-economic energy models with behavioral approaches

Classical energy planning models assume that consumers are rational, which is obviously rarely the case. This paper proposes an original method to take into account the consumer's real behavior in an energy model. This new hybrid model combines technical methods from operations research with behavioral approaches from social sciences and couples a classical energy model with a Share of Choice model

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Mixing Technological and Behavioural Data in the Development of Energy Policies

Optimisation models for environmentally compatible energy planning based on the concept of economic equilibria share a common flaw that stems from their neoclassic roots: the hypothesis of a perfect information and the hypothesis of perfect economic rationality. One of the possible ways how to circumvent this issue, the method we propose first, consists in soft-linking data from sociological surveys that determine technical coefficients for the energy system optimisation model, creating a hybrid approach of coupling a deductive engineering model with typical inductive methods of social sciences. Consumer behaviour is described via usual technological attributes and used in virtual process technologies, keeping the model and data format compatible with all the tools and user interfaces already developed for energy planning models, including International Energy Agency (IEA) supported software platforms. The approach, called Social MARKAL and demonstrated as an example on the technology of lighting bulbs, can be extended to all demand sectors and to all models based on the concept of economic equilibria. The second proposed approach proposed goes even further by applying the methodology called Conjoint Analysis to find the "Willingness To Pay". The method can be applied on immaterial goods like insurance or air ticket pricing and here it is applied on energy services considered as a service, far from usual method of considering it as investment. Both methods eliminate the systematic error on the demand side where the efficiency of demand-side management measures is over-optimistic, which may lead to inaccurate decisions and poor policies. The improved model is thus better suited to build long term policies that are not solely based on technology progress but also taking into account social change. The most important innovation is that the energy consumer behaviour has been brought to the same mathematical optimisation platform and evaluated together and as a complement to technology change

Social MARKAL: Incorporating behavioral parameters

Shifting the modelling scale from original country model formulation down to region, city, community brings new challenges on modelling the demand side. Increasing number of decision makers making frequent decisions on small amounts, often without information, do not always behave rationally. An approach to address a systematic error of about 30% is presented. Energy consumer behaviour is measured by sociological surveys and included into model via additional equations as virtual technologies

Extension of the Social MARKAL Concept to Residential Heating in TIMES Romania Country Model

MARKAL is an energy-environment optimisation framework based on the concept of economic equilibria. Social MARKAL is an extension elaborated to put in competition tangible technologies with consumer behaviour described as virtual technology. In this paper, application of a concept initially used for residential lighting is extended to an another technology, residential heating, while changing both the scope from a city model to a country model, and the tool for TIMES model generator, the successor of the MARKAL. Residential heating, a tangible technology, is decomposed into three virtual technologies: envelope, heating system and consumer behaviour, allowing the modeller to put in competition, within the same modelling framework, technology progress and behavioural change, as a further step to design better public policies

An Energy Optimization Framework for Sustainability Analysis: Inclusion of Behavioral Parameters as a Virtual Technology in Energy Optimization Models

This chapter introduces an innovative approach that combines the deductive method used to construct normative energy-economy models and the inductive method of social sciences. Consumer behavior is described via technological attributes and used in virtual process technologies in an energy optimization framework. The main finding is that it is possible to evaluate consumer information and behavior together with technological progress and integrate them on the same modeling platform. The approach eliminates the systematic error on the demand side where the efficiency of demand-side management measures is over optimistic, which may lead to inaccurate decisions and poor policies. Thus, this method paves the way to a new stream in energy modeling

Introducing Harmful Low Energy Technology Disrupts in Europe: Shouldn't We Have Considered Consumers First?

Regulations around the world are forbidding incandescence bulbs in an attempt to curb electricity consumption. However, lighting occupies a very small share in the total electricity consumption. The replacement technology, mostly fluorescent bulbs count among drawbacks a negative impact on human health and increasing issues for their ecological elimination. Consumers feel attached to the incandescent bulbs but gradually moving to low consumption bulbs. In this paper, we list the disadvantages of fluorescent bulbs and examine some consumers' relationships with light bulbs. This is to add further elements to shift the debate away from electricity savings towards ecological and health concerns