"Government is not reason; it is not eloquence; it is force. Like fire, it is a dangerous servant and a fearful master." - George Washington.
We commonly hear claims like "Someone should do something!" or "There ought to be a law ...". Before a government agency runs off and tries to save the world, we need to consider something very important: static inertia works against action, especially collective action. What I mean is, it is hard to change the "at rest" state of things. It is also hard to make things different from the way things are now, unless the intent is that we all just let go and let things return to the "at rest" state. Put in more basic terms, it is always harder to effectively do something, than not.
This concept is not new. It is common sense that it takes resources and work to keep things organized. In science, the concept is called entropy, which is the tendency for ordered things to become disorganized. In political philosophy, the concept ultimate "at rest" state would be anarchy. I think of the difficulties of public policy related to working against anarchy as overcoming social entropy.
What this means is that for every public policy proposal, we have to think beyond the intended goal. There must be controls for enactment, enforcement, efficacy, and efficiency.
Enactment is about policy become reality, being instantiated. Typically this is begun by legislative action. Zero-based budgeting and funding is generally considered but not always (see the modern US Congress). How do we pay for policy x? Generally public revenues are in the form of taxes or fees or penalties.
Taxes themselves are of course a form of public policy and suffer from the same provisos against government action. I suggest the least obnoxious form of taxation is a consumption tax on complementary goods should be the starting point (and ending point) for all public expenditure. An excellent example would be a gasoline tax dedicated to public highway construction and maintenance.
Enforcement is where things can get really sticky. The two main reasons for this are:
1) unintended consequences - Think of how other things are affected indirectly: will people spend less or save less? Will they become less self-reliant? Will we unwittingly reward immoral or illegal behavior?
2) enforcement as its own end instead of means. Think of the county sheriff who is under pressure to fund local government with traffic and parking ticket quotas. Or the seizure of real property tangential to a crime for the funding of government budgets.
Quality measures like efficacy and efficiency are also important and frequently overlooked. Efficacy is about how well things work as planned and designed. An illustrative example here is mandatory education: do we have more or fewer people with secondary school educations entering the workforce (notice I did not say diplomas) than we might have had otherwise? Unintended consequences come into play here as well. Efficiency is about optimum outlay of resources during the execution of the policy itself. Think of the idea behind competitive bidding.
All four of these ideas are given short shrift in public policy debates. If we critically assess with honesty most congressional acts, state agencies and even local ordinances, we would find they are of questionable value, at best, and many are simply not worth it.