Methods for the Analysis of Longitudinal Dyadic Data with an Application to Intergenerational Exchanges of Family Support

Data on pairs of subjects (dyads) are commonly collected in social research. In family research, for example, there is interest in the extent of agreement in family members' perceptions of relationship quality or how the strength of parent-child relationships depends on characteristics of parents and children. In organisational research, cooperation between coworkers may depend on factors relating to their relative roles and company ethos. Dyadic data provide detailed information on interpersonal processes, but they are challenging to analyse because of their highly complex structure: they are often longitudinal because of interest in dependencies between individuals over time, dyads may be clustered into larger groups (e.g. in families or organisations), and variables of interest such as perceptions and attitudes may be measured by multiple indicators. The principal aim of the proposed research is to develop new methods for the analysis of longitudinal multivariate dyadic data.

While these methods have a number of potential applications, this project focuses on one important case study: the analysis of exchanges of support between parents and their adult children, using data from the British Household Panel Study and Understanding Society (or UK Household Longitudinal Study, UKHLS). Substantive questions to be investigated include:

- What characteristics are associated with giving and receiving support for respondent-parent and respondent-adult offspring dyads? To what extent is the giving and receipt of help persistent over time for a given dyad? And to what extent is the level of exchange associated with lifecycle events?

- What is the level and nature of reciprocity of exchanges?

- For respondents with non-coresident parents and adult offspring, are norms of reciprocity strained where there are competing demands on respondents' time and resources?

- To what extent are financial transfers and 'in kind' transfers (i.e. spending time to help someone) complementary and to what extent do they appear to be substitutes? How does this depend on the socio-economic circumstances of the donor?

We propose a general latent variable modelling framework for the analysis of exchanges between respondents and their parents and adult children over time. Our approach will extend existing research in three major ways. First, most previous research has studied exchanges at a cross-section or between two waves. We will use longitudinal data from five waves of BHPS/UKHLS, spanning a 16-year period, which permits examination of associations between exchanges of support and changes in donor and recipient circumstances over time. Second, it is common to analyse support given separately from support received, which precludes the study of reciprocity. We propose a joint model of bidirectional exchanges with support given and support received treated as a multivariate response, and covariances between responses measuring the extent of reciprocation between generations. Third, family support is measured by a set of binary indicators of different kinds of help. The widespread practice of taking the sum score across items implicitly assigns equal weight to each indicator. We will instead specify a latent variable model that relates the binary items to underlying variables representing overall helping behaviour. The model will be extended to include indicators of financial transfers between family members. Sensitivity of results to measurement error and non-random dropout will also be considered.

Project outputs will include both methodological and more substantively-oriented articles to communicate the research to social scientists. R routines will be written to implement the proposed methods. Extensive online resources will also be produced, including detailed instructions of how to conduct analyses in R, discussion of modelling decisions, and interpretation of results.

WHO WILL BENEFIT?

We expect two main user groups to benefit from the research:

-GROUP 1. Academics and researchers from the public and private sectors with interests in the analysis of dyadic data on interpersonal processes within clusters (e.g. families, organisations); examples include cooperation between work colleagues, agreement between workers and managers in perceptions of organisational efficiency, and frequency and nature of communications between employees and their clients. Researchers may also apply the proposed methods to special cases within our general framework, for example cross-sectional clustered dyadic data.

-GROUP 2. Researchers, policymakers and their advisers, NGOs, think tanks and the wider public with interests in substantive findings from research on patterns of transfers (financial and 'in-kind') between generations of a family over time.


HOW MIGHT THEY BENEFIT?

-GROUP 1. The project is primarily concerned with the development of methods for the analysis of longitudinal multivariate dyadic data, and to enable others to use these methods in their own research through provision of free software and online resources. We will disseminate the use and interpretation of our methods, building up from simple special cases, using exemplars from our analysis of intergenerational exchanges to demonstrate the range of research questions that can be addressed using these methods. The proposed research will bring together several areas in modern social statistics, for example: latent variable modelling, multilevel modelling, longitudinal data analysis, joint modelling of mixed response types, mixture models for zero-inflated data, models for non-random attrition, models for measurement error, and computational methods for large and complex datasets. The research will therefore contribute to the ESRC's long-term strategy of enhancing the quantitative skills of UK social scientists, complementing activities of other ESRC investments such as the National Centre for Research Methods.

-GROUP 2. Social mobility has risen up the policy agenda in the UK under the Coalition government and the current administration, yet much of the evidence is based on a narrow range of sources. This project will contribute new insights into transfers between generations (financial and otherwise) that could help to inform debate on ways in which advantage is transmitted from parents to children. Policymakers and their advisors, especially in the Social Mobility and Child Poverty Commission, and Department for Work and Pensions; and think tanks such as Institute for Public Policy Research, Social Market Foundation, and Bright Blue; will be important audiences here, as well as the wider public.

There is considerable concern amongst policymakers and NGOs about the prospects for older people being left without adequate support, in the light of shrinking social services and possible reductions in the supply of unpaid care. The project's findings will feed directly into this debate by helping to identify particular groups who are risk of lacking support as they age, by examining the patterns of support given and received within families across generations. Department of Health officials responsible for social care, NGOs such as Age UK and Carers UK, will be important audiences here, as well as local government (the Association of Directors of Social Services, for example, and the Local Government Association).

We anticipate that our research will be used by NGOs in their lobbying work with government, and in their awareness-raising activities more generally. We aim for it to inform future national policy development on social mobility, and both national and local policies on support for unpaid carers, and for older people with unmet needs.

Details of activities designed to reach these two broad user groups are given in the Pathways to Impact attachment, and under Academic Beneficiaries above.