34. ←. The levels of professional and regional bargaining (national, provincial) play a minor role and are a variant of sectoral collective bargaining: the regional level is relevant in Austria, Germany, Spain and France, but does little to decentralisation in these countries, since conventional wage rates are generally harmonised between regions in the same sector. Recently, there has also been a step towards the integration of labour and employee agreements. Finally, the quality of labour relations, in particular the trust between the social partners, the ability to apply the conditions laid down in collective agreements and the ability of employers` and trade union organisations to monitor the behaviour of their electorate at lower levels, may make the difference between formally similar systems.  Visser, J. (2018), “Extension policies compared: How the extension of collective agreements works in the Netherlands, Switzerland, Finland and Norway”, in Hayter, S. and J. Visser (eds.), Collective Conventions: Strengthening Labour Protection, International Labour Organization, Geneva. Collective bargaining can also help to correct market failures (e.g. (B asymmetry of information and bargaining power between workers and employers, which may reflect monopsonia and other frictions in the labour market). It reduces transaction costs related to individual negotiations. It can ensure that workers` demands for higher wages are heard, avoiding excessive staff turnover and limiting the scope of costly complaint and complaint handling procedures.
22. ←. In order to avoid losses of members, German employers` organisations have created in Germany a specific form of affiliation in which companies are not bound by collective agreements (ot (without collective agreement), cf. Schulten and Bispinck (2014). In countries where negotiations take place mainly at company level, tariff coverage is generally less than 20% (the Czech Republic and Ireland are the only exceptions). In these countries, coverage tends to go hand in hand with trade union membership, as a trade union or workers` representation in the workplace is a necessary condition for negotiating a collective agreement. Higher agreements (or similar regulatory mechanisms such as the Modern Awards in Australia or professional employment colleges in Ireland) may set some general standards for minimum wage and work organisation, thus limiting to some extent the erosion of coverage. Finally, among the countries where collective bargaining is dominant at the enterprise level, Japan is characterized by a significant and unique degree of coordination (Shunto).
This age effect could also mask a cohort effect when younger generations of workers consistently have less propensity to unionize than previous generations. This reduced propensity for trade union organization could be due to a variety of factors, including changes in preferences or changes in the institutional environment for collective bargaining. Workers who grow and “learn” something about the labour market in an environment where union organization is more limited and less effective, because unions have less power or are less socially appreciated, may thus have a lower propensity for union organization (Bryson and Davies, 2018; Visser, 2002). Most empirical studies show that changes in preferences do not explain much of the decrease in density (see Box 2.2 below). However, studies show that individuals are increasingly willing to join a union after workers have witnessed workplace membership “through sampling” or “union movement through social interaction” (Bryson and Gomez, 2005; Bryson and Davies 2018). In this sense, the decrease in union density could be a snowball phenomenon: after an initial decline, further declines could result in workers from younger cohorts being less exposed to the advantage of union organisation and trade unionism by substitutes. . . .