Noted economist and cryptocurrency skeptic Nouriel Roubini has said Facebook’s soon-to-be unveiled cryptocurrency, reportedly called GlobalCoin, is not really crypto.

In a conversation with CoinDesk, Roubini – also nicknamed “Dr. Doom” for his prediction of the financial crash in 2007 and 2008 – said:

“It has nothing to do with blockchain. Fully private, controlled, centralized, verified and authorized by a small number of permissioned nodes. So what is crypto or blockchain about it? None.”

Indeed, according to recent reports, the social media giant has signed up more than a dozen backers for its GlobalCoin cryptocurrency, a stablecoin apparently to be backed by a basket of fiat currencies. Each of the new backers – which reportedly include Visa, Mastercard, PayPal and Uber – will invest roughly $10 million in the project as part of a governing consortium for the cryptocurrency.

While he acknowledged that specifics of the project are not yet known (but are expected to be revealed in a white paper Tuesday), Roubini suggested that it is unlikely that GlobalCoin would use common blockchain technologies such as proof-of-work or proof-of-stake. “Why would they?” he said.

And while many in the crypto community have also criticized those calling Facebook’s token a cryptocurrency, the economist denied that he shared any common ground with the “crypto faithful.”

He told CoinDesk that he has gone on record as saying that “enterprise DLT [distributed ledger technology] is blockchain in name only … so some crypto faithful may agree on that.”

Roubini concluded by saying:

“But in my opinion, public decentralized trustless blockchain is a pipe dream … so we disagree on 99% of [the] substance.”

Click here to see our comprehensive guide to Facebook’s GlobalCoin.

Nouriel Roubini image via Shutterstock