ISTANBUL, Turkey — Turkish tax collectors are showing up in nightclubs, visiting soccer stadiums, and even questioning brides and grooms as they struggle to force people to pay up in a country where about half the workforce evades taxes.

Finance Minister Kemal Unakitan, offering a carrot to go with the stick, on January 1 hosted a televised ceremony where he handed out plaques to people who paid the highest taxes that year. The Tax Administration even held a contest in which children wrote poems lauding the benefits of tax paying.

“Except for people who work for the government, probably everybody is in some way evading taxes,” said Soner Cagaptay, an analyst at the Washington Institute for Near East Policy. “It’s rampant. It’s across the board.”

The government needs to increase income tax revenue to pay debts that equal about 50% of gross domestic product as it strives to convince the European Union it is ready to join the bloc. The International Monetary Fund is also demanding improved tax collection as a condition of the $10 billion in loans it has extended to Turkey.

Tax evasion “reduces the overall growth potential of the Turkish economy” because unregistered companies cannot apply for loans, the Paris-based Organization for Economic Cooperation and Development said in an October report.

Only 4% of Turkey’s 71.8 million people were registered taxpayers in 2004, according to an OECD survey of 45 countries. By comparison, 76% of American citizens were registered taxpayers.