The pay gap between bosses and their workers has increased in every region worldwide since the 2008 financial crisis, according to the latest research.
Using figures from its online pay database, global management consulting firm Hay Group found that the wage gap between skilled manual, clerical, supervisor or graduate-entry jobs and senior managers was rising in twice as many of the over 110 countries surveyed as it was falling.
"The potential for a large job pay gap to cause discontent among the workforce is huge," warned Ben Frost, a consultant at Hay Group, in a news release about pay disparity.
The pay gap has increased by 2.2 percent in Europe since the start of the global recession—the smallest gain of any region in the world. In contrast, North America and Asia have seen rises of 7.2 percent and 12.5 percent respectively. The U.S. alone saw a 10.6 percent increase.
Salaries across the globe are set to rise by 5.4 percent on average in 2015, compared to 5.2 percent last year, according to Hay Group. But this average masks "a significant slowdown" in emerging markets like Brazil, Russia and Ukraine, with workers in these countries set to suffer real wage cuts of 0.4 percent, 0.7 percent and 3.9 percent respectively.
Since the crisis, the European Union has introduced rules that cap bankers' bonuses to one times salary, or twice if shareholders approve.
"The pay gap has accelerated as globalization opened up workforces and lower level jobs are increasingly automated and off-shored. This reduces the number of jobs available and increases competition for those left, keeping pay down," said Frost.
"In contrast, pay is going up for senior managers where skills such as emotional intelligence, creative thinking and advanced judgement are in high demand and short supply. In addition, senior managers are increasingly being asked to take on more responsibilities and more complex work."
Europe was the region where the greatest number of countries had experienced a decrease in the pay gap, with these including Switzerland, France and Poland.
"In response to the recession, many companies in Europe introduced communal pay cuts to avoid job losses," said Frost.
"In comparison, U.S. companies more frequently cut jobs and asked the remaining senior managers to expand their scope of work during the recession. Many of those who remained employed received a pay increase as compensation for their expanded role, leading in part to the widening job level pay gap."
In a survey published this month, the U.K.'s Institute of Directors reported that its members saw public anger over high executive pay as the biggest threat to trust in businesses.