Referenda are decided by weighted votes. Everyone can vote, but their votes are weighted based on how wise their previous votes were in hindsight, as determined by the popular vote.
Everybody has the right to vote directly on a referendum; either when its proposed or two years later. If you vote on it when its proposed, you are trying to predict whether it will benefit the country or not. If you vote on it after its been adopted or defeated, you are voting on whether it benefited the country or not. Whenever the (unweighted) majority approves of a vote you cast, your vote gets increased weight according to an algorithm.
This system of weighted rule, or histocracy, ensures that power goes only to the wise, and only to those who do not abuse it. Everyone is a senator whose constituency is the future.