This surprise endorsement of the 'No' camp was welcomed by Renzi's opponents, including Five Star Movement leader Beppe Grillo. The head of the 'anti-establishment' party celebrated the news on his blog - neglecting to mention the paragraph where the Economist cites "the spectre" of the Five Star Movement leader as Prime Minister as one of the biggest risks of a 'No' victory.
It is worth noting that even if the Five Star Movement were to win snap general elections after a 'No' victory - a possibility, since the party is currently enjoying a wave of popularity - Grillo himself does not stand to become prime minister.
The influence of both Grillo and the party are highly likely to increase if 'No' performs as well as predicted: When the final polls before a 15-day polling blackout were published last Friday, the 'No' camp was shown to be leading by around five points.
Grillo has recently toned down his anti-EU views, clarifying in a blog about the UK's Brexit vote that he and the party supported "reform from within" the union. But his anti-euro stance (he still favours a referendum on Italy's membership of the single currency) and the prospect of a relatively inexperienced party in power would likely have repercussions on EU stability.
Still, the most likely scenario if Renzi's opponents win is not an immediate general election, but an interim technocratic government tasked with making changes including the electoral law. This is the option supported by the Economist.
The Economist's argument that Renzi's resignation will not be the disaster that some members of the media have made it out to be is fair.
Renzi himself has recently worked hard to calm worries over a possible 'No' vote, assuring voters that he doesn't "anticipate any major disasters" should his reforms fail: Since a vote for 'No' is a vote for things to stay as they are, he has said it would not cause major upset or have a significant effect on global markets.
Legitimate concerns over Renzi's reforms include potential corruption encouraged by a non-elected Senate, and a lack of checks and balances created by putting more power in the hands of the PM.
But the Economist's main critique of Renzi's reforms is that they "fail to deal with the main problem, which is Italy's unwillingness to reform". The paper lambasts the PM for "wasting time" on "constitutional tinkering" and claims that he should instead have argued for wider judiciary and school reforms.
It argues: "The sooner Italy gets back to real reform, the better for Europe."
Yet a 'No' vote is unlikely lead to any specific reform, largely due to the diversity of groups involved in the 'No' campaign, from Grillo's populist Movement to the far-right Northern League to trade union CGIL.
One of the main arguments of the 'Yes' camp has been that passing this reform would leave the door open for more comprehensive change in the future, and Renzi reiterated this view at a discussion held by La Stampa daily on Friday, where he brushed off the Economist's argument.
The beleaguered PM told the audience that in his view, real change can only be achieved by a strong, stable government, and so the "real reforms" the British paper supports would not materialize under a technocratic government.
He argued that such a government would not act in the interests of the 'Italian people' but would rather be likely to go along with the will of Brussels as it would have little mandate to do otherwise.
Renzi also pointed out that five of the prominent 'No' campaigners are former premiers who promised reforms but never delivered. "If the Italians want to entrust themselves to them, go ahead."
All sides seem to be agreed on the fact that Italy is badly in need of reforms, so the question facing Italians is whether they believe Renzi's proposals would be a good start which would make further reform more likely, or whether they're willing to place their trust in his opponents to come up with a better idea.