The impact of trade unions and government party orientation on income inequality: evidence from 17 OECD economies

Purpose - Despite the existing conceptual analysis on the impact of trade unions on employees' welfare and the wider economy, the mediating effect of political party orientation (i.e., right, centre and left) on income inequality remains under researched. In this paper, the authors empirically explore the relationship between the nature of political party orientation, trade unions and income inequality. Design/methodology/approach - The authors use three different measures of income inequality and dummy variables that capture government party orientation with respect to economic policy for a panel of 17 OECD economies over the period 2000–2016. The authors employ a panel fixed effects approach and the Driscoll and Kraay's (1998) nonparametric covariance matrix estimator. Findings - The empirical evidence indicates that strong unions and, to some extent, left party governance, are fundamental institutional elements to combat rising levels of income inequality whilst countries dominated by right-wing political parties appear to exacerbate income inequality. The results pertaining to the impact of centrist parties on income inequality are ambiguous suggesting that a potential fragmentation may exist in their political approach. Originality/value - The evidence generated can have significant policy ramifications in alleviating rising levels of income inequality as well in relation to the declining unionization rates observed across advanced economies.