> They were always careful to grow just enough that none of it ends up unsold.
It is a market. However much they grow, exactly that much will end up sold. They'll drop the price if there is unsold inventory to sell it.
They can't be doing a physical estimate of how much lettuce people eat. If there was any variance at all in how much lettuce gets eaten (which there is) then there'd be constant lettuce shortages where the shelves were empty. That doesn't happen, so we can tell that they are using price signals to control how much gets sold.
It is a market. However much they grow, exactly that much will end up sold. They'll drop the price if there is unsold inventory to sell it.
They can't be doing a physical estimate of how much lettuce people eat. If there was any variance at all in how much lettuce gets eaten (which there is) then there'd be constant lettuce shortages where the shelves were empty. That doesn't happen, so we can tell that they are using price signals to control how much gets sold.