Applications of multilevel modelling: An evaluation of the assumption of no correlation between explanatory variables and random effects
The Faculty of Social Sciences, University of Stirling, is advertising a fully-funded PhD scholarship available on a 1+3 or +3 basis. A ‘1+3’ award is a four-year programmes covering a one-year Masters course (MSc Applied Social Research, Social Statistics and Social Research pathway) followed by a 3-year research degree. A ‘+3’ award constitutes a 3-year research degree and is available to candidates who already have suitable Masters level training. The successful candidate will be supervised by Professor Paul Lambert and Dr Rosie Seaman, both of the Social Surveys and Social Statistics research group within the Faculty of Social Sciences.
This project is concerned with a methodological question about how multilevel models are used in applied social research. Multilevel models are important statistical methods that are often used in social science projects. Nevertheless, when multilevel models are applied, they frequently violate a statistical assumption about their specification, namely that the estimated random effects are uncorrelated with explanatory variables (‘NCRX’). If there is a correlation, it has been demonstrated that parameter estimates could be biased and/or inefficient. Although the statistical issues surrounding the NCRX assumption have been demonstrated, there remain many research applications where the assumption is not fully explored, and there are divergences between social science disciplines in how seriously the assumption is taken.
This PhD project will (I) review methodological and applied research literature on the NCRX assumption across social science disciplines, (2) analyze simulated data to explore the importance of the assumption in different contexts, and (3) use the ‘Understanding Society’ secondary social survey (special license versions) to carry out two case studies on socio-economic inequalities by occupations and health inequalities by localities in which the NCRX assumption is likely to be relevant. These two case studies are tailored to complement the applied research interests of the supervisors.
The project will provide numerous training opportunities in social statistics and social research. On completion of the PhD the candidate can expect to have developed a range of valuable career skills and to hold very favourable career prospects.
• an annual maintenance grant at the RCUK rate (2020/21 rate: £15,285)
• fees at the standard Home rate (equivalent to approximately £4500 per annum)
• students can also draw on a pooled Research Training Support Grant, usually up to a maximum of £750 per year
How good is research at University of Stirling in Social Work and Social Policy?
FTE Category A staff submitted: 32.97
Research output data provided by the Research Excellence Framework (REF)
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