A HEALTHY ECONOMY
Is when as many people as possible are doing things that other people value. Uncertainties about the future cause people to more carefully assess what things they most value and to reject things of marginal value. Creating as certain a future as possible, even if the general outlook may be worse, allows people to maximize their expenditures (positive valuations of other peoples efforts).
Legislation with future enacting dates that may have great functional impact will cause people to naturally wait until the effects are known, thus forestalling any positive behavior.
Knowledge of a positive future = healthy economy, present and future
Knowledge of a negative future = reduced economy present, maximized economy within the circumstances future
Uncertain knowledge of future = minimal economy present, less than fully maximized future