Expat tax is most benign in the United Arab Emirates, Russia and Hong Kong, according to a new survey by Mercer Consulting. Mercer's 2007 Worldwide Individual Tax Comparator Report shows that Belgium, Denmark and Hungary are the least attractive places to work for expats from a personal tax perspective. The survey analysed the tax and benefits systems across 32 countries, focusing on personal tax structures, average salaries and marital status and is used by multinational companies to structure pay packages for their expatriate and local market employees. The UAE was found to have the most attractive tax environment for single expats as it does not assess any income tax, and the country's social security contributions amount to only 5 per cent of an employee’s gross salary. Russia, second in the rankings applies a flat tax of 13 per cent across all income levels, while Hong Kong was placed 3rd, with taxes and social security contributions at 14.2 per cent of gross base salary. The UK ranks joint 14th, whilst Ireland was in 18th place, Spain 19th, and Switzerland 21st.