Valikoitumista vai käsittelyvaikutusta? ESG-raportoinnin aloittamisen ajoitus ja yritysten suoriutuminen eurooppalaisessa merilogistiikassa

In the last decade, the requirements of sustainability reporting have increased, especially in the European Union area. The goal has been to enforce transparency, reliability and consistently of sustainability information across all companies. This thesis examines whether earlier voluntary ESG disclosure in the format of sustainability report is associated with improved financial, operational or reputational performance. Using a panel dataset of 99 European maritime logistics firms over the period of 2010-2024, the study applies pooled OLS, Random Effects and Fixed Effects specifications to analyse the relationship between ESG disclosure timing and accounting-based performance measures of ROE and ROA as well as ESG scores. Simple descriptive statistics reveal that early adopters significantly outperform late adopters and non-adopters across all three dimensions. However, the regression results demonstrate that these advantages are largely driven by firm-level heterogeneity. When controlling for firm size, age, and other characteristics in the preferred Random Effects specification, the association between early ESG adoption and firm performance becomes statistically insignificant. The findings suggest that the observed performance gap results from selection effects rather than a causal treatment effect. High-quality, resource-rich firms self-select into early reporting, but disclosure timing itself does not independently drive superior financial or operational outcomes. These null findings contrast with prior meta-analyses suggesting a universal positive link, instead supporting critical literature that identifies reverse causality and selection bias in the relationships between ESG and financial performance. Consequently, the thesis argues that ESG disclosure functions primarily as a tool for legitimacy maintenance rather than a direct driver of financial value, suggesting that managers and policymakers should view reporting as a complement to and not as a substitute for operational sustainability improvements.