Subjective well-being (SWB) - here understood as a person’s cognitive and affective evaluations of his/her life as whole and with regard to particular aspects of his/her life (Rees et al. 2010) - is an important concept. Its relevance arises for a number of reasons, including its important role in understanding variations in the well-being of populations and in identifying what aspects and factors are most salient in people’s lives. As such, SWB has received growing attention, both from academia and the political world.

Most SWB studies have, however, focused on adults’ SWB, whereas interest in children’s SWB is quite recent (Casas 2011; Ben-Arieh 2012). The United Nations Convention on the Rights of the Child’s acknowledgment of the importance of taking into account children’s views in matters that affect their lives heavily contributed to this recent trend.

Current studies on the SWB of children have produced evidence on how children’s life satisfaction seems to be important to their positive development, but also in identifying possible risks and vulnerabilities (Rees et al. 2010). Moreover, children’s SWB can act as an important buffer against negative outcomes. On the other hand, studies focusing on what may affect children’s SWB have suggested that children’s happiness may be influenced by factors such as housing, safety, bullying, school achievements or social interactions (Bradshaw et al. 2013). However, much is still to be learned about these relationships and deeper research is necessary in order to grasp a more complete picture of what impacts children’s SWB. It was the recognition of this need that motivated this Special Issue’s focus on children’s SWB, for which the departing point is the unique Children’s Worlds: International Survey of Children’s Well-Being (ISCWeB) (http://www.isciweb.org/).

ISCWeB is a world-wide research project on child subjective well-being, hence it is a distinguished project in the field.

The ISCWeB project is based on the idea that one of the most important factors in assessing whether a particular environment is conducive to children attaining their best potential is their own subjective sense of well-being. This is best investigated by asking children directly and by allowing them to give an assessment of their own well-being. Thus, the survey is based solely on children's own evaluations, perceptions and aspirations. In addition, the survey focuses on subjective well-being in mid-childhood, that is, from the ages of 8 to 12 years.

Furthermore, the project is an international, inter-cultural and multi-linguistic survey in which a variety of countries and cultures take part. Consequently, it provides both local and comparative insight into the lives of children in a diverse range of cultural contexts, and substantial new information about how children live their lives. These national and international perspectives make it possible to better our understanding of the nature of childhood in different contexts, and draw implications for local, national and international policy. Additionally, the use of newly developed quantitative assessment instruments for children, which comprise various life domains, offers important insight into methodological issues in comparative research with children.

Work began in 2009 when a group of researchers, mainly from the International Society for Child Indicators (ISCI) with the support of UNICEF, acknowledged the potential need for an international survey of children's subjective well-being. This resulted in a draft questionnaire. This questionnaire was then tested in two series of small scale pilots in the summer and autumn of 2010 and in the first half of 2011 in a total of nine countries (Brazil, England, Germany, Honduras, Israel, Romania, South Africa, Spain and Turkey), each followed by a review and an evaluation of the questionnaire. This learning lead to the design of separate versions for children aged 8, 10 and 12. The next step was using these questionnaires with large samples across a diverse range of countries. The Special Issue is based on this phase of data collection – ISCWeB First Wave– also known, due to the exploratory nature of the phase, as the ‘deep pilot’.

About 34,500 children from 14 countries – Algeria, Brazil, Canada, Chile, England, Israel, Nepal, Romania, Rwanda, South Africa, South Korea, Spain, Uganda and the US – participated in the this wave, which was conducted between winter 2011 and winter 2012. Using only their own resources, each country aimed to gather the best possible sample and to include as many children as possible, given the time scales and resource constraints. The data collection was done through mainstream schools; in each country the classes (grades) in which the majority of the children were in the targeted age groups were sampled. The original English questionnaire was translated into the language spoken by children in each of the countries, and the questionnaire was tested to ensure children's understanding before being finalised.

The articles included in this Special Issue not only present important findings, but also showcase the ISCWeB project as a whole and offer avenues for further work, based on the pilot data and on the international, representative dataset which is being prepared as we write.

The first two articles of this Issue showcase the scope of the project. Gwyther Rees and Tamar Dinisman present one of the first attempts to assess children’s subjective well-being in a diverse international context, drawing comparisons from eleven countries. Following this, Johanna Wilmes and Sabine Andresen challenge us to carefully consider the influence of dominant western conceptions of well-being, through their comparison of Nepal and Germany.

As an emerging field of study, international comparative work on child subjective well-being poses methodological as well as conceptual challenges. Ferran Casas and Gwyther Rees provide an assessment of which international comparisons offer meaningful information, and where more caution is needed. The study of child subjective well-being is also relatively new within many national contexts, and Daphna Gross-Manos, Edna Shimoni and Asher Ben-Arieh detail the testing of subjective well-being measures amongst a sample of children in Israel.

Childhood, and child well-being, are multifaceted issues and the ISCWeB survey provides access to data on a range of aspects of children’s lives. Family context and participation is of prime importance to children’s well-being, and Monica Gonzalez, M. Eugenia Gras, Sara Malo, Dolors Navarro, Ferran Casas and Mireia Aligué explore this among Spanish children. Life experiences and changes in children’s circumstances in eight countries are explored by Carme Montserrat, Tamar Dinisman, Sergiu Bălătescu, Brȋndusa Antonia Grigoras, and Ferran Casas. Bullying can be a devastating experience, and Habib Tiliouine examines its prevalence and impact among Algerian children.

Different aspects of children’s lives can act alone and interact to impact subjective well-being. Bong Joo Lee and Min Sang Yoo explore associations between family, school and community factors and subjective well-being, and how national context impacts associations, across eleven countries. Ecological perspectives on child well-being stress the importance of a wide range of interacting contexts, and Lisa A. Newland, Michael, J. Lawler, Jarod T. Giger, Soonhee Roh and Eliann R. Carr explore these using a relationship-based framework in a rural mid-western US sample. Access to resources varies markedly according to national context, and Jorge Castellá Sarrierra, Ferran Casas, Lívia Maria Bedin, Daniel Abs, Miriam Raquel Strelhow, Daphna Gross-Manos and Jarod Giger explore associations between material resources and well-being across eight countries.

An internationally comparative study offers unique opportunities not only to measure well-being but also to examine how national, cultural and policy contexts might facilitate improvements. Shazly Savahl, Sabirah Adams, Serena Anne Isaacs and Roseline September provide an analysis of how the South African context might shape levels of children’s subjective well-being. In the final article, Jonathan Bradshaw offers an overview of current knowledge of children’s subjective well-being in international context and makes the case for further studies such as the Children’s Worlds survey.

The broad scope of the articles presented in this Special Issue offer some insight into the diverse opportunities available through the ISCWeB study. They also demonstrate that much remains to be learnt about children’s well-being, its drivers, and its impacts on life chances through the life course. We hope that the research presented here acts as a stimulant to researchers, policymakers, and funders, to continue developing this emerging and exciting field.