This study investigates the key financial factors influencing the market value of listed Greek companies over the period 2009–2023, with particular emphasis on tax avoidance, as well as on variables such as capital structure, firm size, profitability, and liquidity. An unbalanced panel dataset of 222 firms was employed, and panel data econometric methods were applied, using fixed effects (FE) estimators with robust standard errors, following Hausman and Wooldridge specification tests. The results indicate that the effective tax rate is negatively associated with firm value (Tobin’s Q), suggesting that lower tax burdens may be linked to higher market valuations, albeit with a moderate effect. Leverage consistently shows a negative and statistically significant relationship with value, implying that excessive debt undermines market performance. Firm size also has a negative effect on firm value, possibly reflecting
reduced growth opportunities in larger firms. In contrast, profitability emerges as the strongest positive determinant of firm value, while return on equity (ROE), used as an indirect proxy for dividend policy, exhibits a negative association—likely due to the influence of leverage. Liquidity remains positive but statistically insignificant in the main model, indicating that intra-firm variations in liquidity have no substantial impact on value. This research contributes to the literature by providing empirical evidence from the Greek market, particularly during the period of economic crisis and recovery. The findings highlight the importance of a balanced tax strategy, prudent debt management, and the enhancement of operating profitability as key drivers for improving market value. Furthermore, the study underscores the need for careful interpretation of indicators such as ROE when used as substitutes for dividend policy
and reveals the limited effect of liquidity within firms.

JEL Classification: D22, G32, H25, H26, H32, L25, M21