E/C.12/PRT/CO/4 (c) Reinforcing the support for jobseekers, with special focus on the longterm unemployed, including by providing them with adequate training to enhance their skills. In that regard, the Committee refers the State party to its general comment No. 18 (2005) on the right to work. Gender wage gap 9. The Committee is concerned that the gender wage gap, which is discriminatory against women, although lower than the European average, is still considerable owing to occupational sex segregation (arts. 3 and 7). The Committee recommends that the State party take measures to close the gender wage gap, including efforts to combat horizontal and vertical occupational sex segregation in the labour market, and to ensure the effective implementation of the principle of equal pay for work of equal value. Temporary employment, undeclared work and “dependent” self-employment 10. The Committee is concerned at the high incidence of temporary employment in the State party, including involuntary temporary employment, as well as at undeclared work, which is estimated to produce income representing over 20 per cent of gross domestic product. It is also concerned about the phenomenon of “dependent” self-employment (“falsos recibos verdes”) and about the negative impact that all of those forms of employment may have on the enjoyment by workers of their rights under articles 6–8 of the Covenant (arts. 6–8). The Committee recommends that the State party: (a) Take all appropriate measures to progressively reduce the use of temporary employment, including by generating decent work opportunities that offer job security and adequate protection of workers, with a view to respecting their labour rights, as set out in articles 6–8 of the Covenant; (b) Step up efforts to tackle undeclared work, including by (i) raising awareness of negative serious consequences for workers in undeclared work and of the benefits of declared work; (ii) providing incentives for regularization and facilitating integration into the regular labour market; (iii) improving identification of such cases, including through the strengthening of labour inspections and training of inspectors on undeclared work; and (iv) providing for deterrent sanctions against employers that use undeclared work; (c) Step up efforts to address the phenomenon of “dependent” selfemployment and ensure that the labour and social security rights of persons under that contractual arrangement are fully guaranteed in law and in practice. Collective bargaining 11. The Committee is concerned that the reduction in the coverage of labour relations by collective agreements and the increasing trend of transferring collective bargaining to the level of enterprises may put employees in a disadvantaged position in the determination of wages and working conditions by direct negotiation (arts. 6–8). The Committee calls on the State Party to take all the necessary measures, including the establishment of effective control and monitoring mechanisms, with a view to ensuring that agreements concluded at the enterprise level fully respect the rights of 4