Should governments adopt supply-side or demand-side economics in managing their nations’ economies?

Question

as detailed as possible

Answer 1

Looking at history, I would say that which approach you focus on is based on the condition of your economy and the political will for the kinds of measures needed by either approach.   Changing from demand to supply side economics requires charismatic and convincing leaders to assure people who are used to demand side measures to trust that supply side moves, most famously sharp cuts in tax rates, will stimulate investment and growth in the manner needed at that point in time.   The credibility of the leader or his or her party is key, as are the people's sense of futility with the status quo.

The same might be true on the demand side.  America is now in a mode where we see the weaknesses of supply side economics, mainly allowing infrastructure to deteriorate beyond a reasonable level, and wide disparities of income distribution.  We may be ready for a string of demand side moves, government spending on infrastructure for example, to stimulate the economy and ensure a sound transportation system for the future.

Answer 2

Neither.

Government cannot manage economies, and should not.  Haven't you noticed the mess we're in?

Answer 3

Why one or the other and not both?

Both supply side and demand side economics have the place, and which one works better depends on what you're trying to do, who you're trying to do it to, and the nature of the economy.

In the end, there is no right answer.  It comes down to your opinion of the merits of each approach.