This study investigates the factors that influence the quality of SDG reporting among Portuguese municipalities. It focuses on municipal characteristics (size, location, financial efficiency, gender of the mayor, and participation in local SDG initiatives such as CESOP_Local), as well as report-specific factors (type of report and reporting framework). A mixed-methods design combining content analysis with panel data regression was employed. An SDG disclosure index was used to analyse commitment and reporting quality on a four-point scale, ranging from no reference to full integration with quantitative indicators and strategic alignment.
The initial sample covered all 308 Portuguese municipalities and targeted sustainability reports (SR) from 2015 to 2024. However, only 29 municipalities had published SRs, providing 67 reports for analysis in the decade following the adoption of the 2030 Agenda.
The results show an overall improvement in the quality of SDG reporting over time, although there were declines during economic downturns. The average SDG disclosure level was 2, reflecting mainly qualitative disclosures with limited quantitative data. Of the municipal characteristics examined, only size had a statistically significant positive effect, with larger municipalities providing more comprehensive reports. At the reporting level, adherence to GRI standards and participation in CESOP_Local initiatives were strongly associated with higher-quality reporting.
These findings contribute to the limited research on SDG reporting by local governments, emphasising the need for standardised frameworks to improve comparability and accountability. As the latest SDSN report indicates that many SDGs are off track, attention should now turn to the post-2030 framework and forward-looking new strategies built on lessons learnt, as suggested by the Pact for the Future. Future research should examine how municipalities prepare for this transition and integrate revised metrics into their reporting. It should also expand analyses to other countries and additional political or institutional factors affecting reporting quality.
