Saving money amounts to producing some wealth without consuming any wealth in exchange (generally because you expect your savings to conserve value, and therefore get the right to consume without producing some time later. Like all bets and promises, sometimes it works, sometimes it doesn't)
That's good for the economy when there is a lack of supply: plenty of people willing to buy stuff while nobody wants to make those stuff. When there's a lack of demand, it doesn't help. When there's a lack of demand, you need to make people consume more, possibly by delaying / alleviating the expectation that they produce something valuable first. This consumption is expected to allow creation of supply. That's the principle of a Keynesian stimulus.
The problem typically associated with massive unemployment is a lack of demand: there are plenty of unemployed people who would like to produce and consume, but they can't find anyone willing to buy whatever they might produce.
Put another way, UBI is a way to raise the velocity of money, the amount of commercial exchanges per amount of time occurring in the economy; saving lowers money velocity.
That's good for the economy when there is a lack of supply: plenty of people willing to buy stuff while nobody wants to make those stuff. When there's a lack of demand, it doesn't help. When there's a lack of demand, you need to make people consume more, possibly by delaying / alleviating the expectation that they produce something valuable first. This consumption is expected to allow creation of supply. That's the principle of a Keynesian stimulus.
The problem typically associated with massive unemployment is a lack of demand: there are plenty of unemployed people who would like to produce and consume, but they can't find anyone willing to buy whatever they might produce.
Put another way, UBI is a way to raise the velocity of money, the amount of commercial exchanges per amount of time occurring in the economy; saving lowers money velocity.