Minimum wages also declined relatively to median wages in a number of countries between the 1980s and 2008. Wage-setting mechanisms also changed: the share of union members among workers fell across most countries, although the coverage of collective bargaining generally remained rather stable over time. A number of countries cut unemployment benefit replacement rates and, in an attempt to promote employment among low-skilled workers, some also reduced taxes on labour for low-income workers (Figure 4). On the one hand, past empirical evidence points to the significant positive impact of reforms on employment levels (e.g. OECD, 2006).