A group of 137 countries and jurisdictions agreed to move ahead with negotiations to address tax challenges of the digital economy, according to a statement released Friday by the Organization for Economic Cooperation and Development (OECD).

A wealth tax is like a property tax, but instead of just taxing buildings and land, it taxes everything someone owns, diamonds, helicopters, paintings, rare pets, you name it. Senators Elizabeth Warren and Bernie Sanders have each proposed that the federal government, for the first time, impose this tax on the ultra-rich — but there's a sizable group of legal scholars who believe the Supreme Court would likely knock this policy down.