There is always an uproar over the amount of wealth held by the top 1% in the world. In January, for instance, Oxfam International published a report that showed that eight men were holding as much wealth as the world’s poorest 3.6 billion. Enter the Giving Pledge.

In a world where such glaring income inequality exists, there is always an expectation that the rich must give back, if only through charity. Warren Buffett and the Bill & Melinda Gates Foundation launched the Giving Pledge in 2010 to help with that.

The initiative aims to encourage billionaires and their families to dedicate the majority of their wealth—at least half—to philanthropic causes, either during their lifetimes or after their deaths.

On Tuesday, an additional 14 individuals and couples from seven different countries added their names to the Giving Pledge, making up the total signatories to 168 individuals or couples from 21 countries.

Melinda Gates said in a statement; range from poverty alleviation and environmental protection to climate change and medical research.

“Philanthropy is different around the world, but almost every culture has a long-standing tradition of giving back,”

“Bill and Warren and I are excited to welcome the new, very international group of philanthropists joining the Giving Pledge, and we look forward to learning from their diverse experiences.”

It is important to note that the Giving Pledge is not legally binding. It is at best a moral pledge that suggests the principle of charity to these wealthy individuals or families. There is no enforcement mechanism that will ensure that the signatories follow through.

In fact, the effect of the pledge may only be felt in the long term if billionaires choose the option of leaving the donations in their wills. Meanwhile, signing to the Giving Pledge is a definite PR boost that could convince onlookers of noble interests.

Check out the list of new billionaire signatories to the Giving Pledge below;

• Leonard H. Ainsworth; Australia
• Mohammed Dewji; Tanzania
• Dagmar Dolby; United States
• Dong Fangjun; People’s Republic of China
• Anne Grete Eidsvig and Kjell Inge Røkke; Norway
• Sir Stelios Haji-Ioannou; Monaco, Cyprus
• Nick and Leslie Hanauer; United States
• Iza and Samo Login; Slovenia
• Dean and Marianne Metropoulos; United States
• Terry and Susan Ragon; United States
• Nat Simons and Laura Baxter-Simons; United States
• Robert Frederick Smith; United States
• Harry H. Stine; United States
• You Zhonghui; People’s Republic of China