Environmental history and living-environment satisfaction among young adults in Nigeria

This preregistration specifies a secondary analysis of the Nigeria Multiple Indicator Cluster Survey 2016–17 linked to satellite-derived environmental data. The study examines whether present-day evaluations of the living environment differ according to the antecedent vegetation history of respondents’ residential localities, while distinguishing that history from subsequent environmental departure and current vegetation state. The primary outcome is satisfaction with the living environment among women and men aged 15–24 years. The focal environmental exposure is the 2005–2014 trajectory in local vegetation greenness derived from MODIS NDVI, modelled conditional on the 2015 departure from that antecedent trajectory, current pre-interview vegetation greenness, and prespecified contextual covariates. The study also evaluates urban–rural heterogeneity, domain specificity across wellbeing outcomes, alternative environmental exposure definitions, rainfall-conditioned estimates, functional form, and spatial residual structure. The MICS data and environmental data existed and were accessible before this preregistration. Prior to registration, questionnaire content, variable coding, sample availability, survey design, environmental exposure construction, linkage completeness, and outcome-blind environmental and spatial diagnostics were examined in order to define the analysis specification. Outcome variables were inspected for wording, coding, availability, and valid-response counts. However, no substantive association between the prespecified environmental exposures and the primary or secondary wellbeing outcomes was estimated or inspected before the present analysis plan was frozen. The preregistration therefore records the hypotheses, estimands, primary model, adjustment set, effect-modification analysis, uncertainty procedure, diagnostic strategy, and sensitivity hierarchy before substantive exposure–outcome results are examined. The analysis is explicitly non-causal. The causal diagrams are used to make assumed data-generating relationships and covariate roles transparent, but the available cross-sectional secondary data do not support identification of a causal effect of historical vegetation trajectories. Results will therefore be interpreted as conditional associations and patterns in living-environment appraisal rather than as causal effects. Any deviation from the preregistered analysis plan will be documented transparently.