One of the most difficult questions to answer, given the extensive black economy, is what the real average wages of Greeks actually amount too. Illegal overtime – with workers’ consent – and invisible earnings from informal jobs and commissions of every kind that are recorded nowhere all create sources of income that are hard to calculate. Informal spending However, they can just as easily be transmuted into spending on a plethora of services, from private lessons and under-the-table payments to doctors to repair jobs carried out and paid for on the understanding that receipts will not be given. Yet another factor makes determining earnings difficult: Research carried out recently showed that about one in two enterprises pays more than the limits set by collective wage agreements. But only in a quarter of the enterprises does this involve the entire work force; in most, it applies to only some of the staff. The survey was carried out in the form of interviews at 2,016 firms in June-July 2002 by INE/GSEE and the Civil Servants Union (ADEDY), in collaboration with a private company. Extra pay for employees is chiefly met with in enterprises employing over 50 workers. Discriminatory treatment The survey discovered that swollen pay packets for the entire work force was the norm for firms that employed from 10 to 19 employees, especially in Thessaly, Eastern Macedonia and Thrace. This practice was found in half of the credit companies in the sample, and is common in the information technology, market research and real-estate sectors. Extra pay for some of the work force was more commonly met with in Attica and on Crete in the construction, transport and haulage and industrial sectors. One in two firms (57 percent) with over 200 employees admitted to such practices. Firms abiding by collective wage agreements are more commonly met with in central Greece, the Peloponnese and central Macedonia, in the catering and tourist sectors and in firms with up to nine workers. But only 32 percent of companies in 2002 linked pay to staff productivity or company profit. Nineteen percent of all firms linked pay to staff productivity, 5.5 percent linked extra pay to positive economic results, while 7 percent took account of both factors.