.but the validity is not questionable if the model correctly shows what will happen to an economy when variables are plugged in and the result predicts actual behavior.
1 - The models have not been so good at predicting actual behavior.
2 - In this particular case the question is the size of the stimulus effect of government spending. You can't measure what the size of the effect from the economic stats before and after the policy, because such policies are not in this case, and in fact are never, the only factor.
Because of the huge numbers of variables, economic models are difficult to produce.
And often in disagreement with each other, and generally unreliable. Probably becoming more unreliable the more they actually drive policy. (For example the belief that there was a long term trade off between unemployment and inflation, caused efforts against inflation to be weaker, eventually resulting in the surprise of "stagflation" with high unemployment and high inflation.)
there are people on SI with no credentials critiquing astrophysicist Steven Hawking
Someone isn't right or wrong depending on their credentials. Is he smarter than me? Sure. Is he more educated in the areas of physics and astronomy and math than I am? Sure. But that doesn't mean that I can't reasonably criticize anything he says, or even anything someone related to space or astronomy. For example his recently expressed worry of alien's invading for the purpose of taking Earth's resources seems rather overblown. Any civilization from another solar system that could get to Earth with enough payload to actually do anything once they get here, would be able to grab far more resources, much easier, elsewhere.
There might be specific exceptions. If they like Earth like planets, and such planets are rare, I suppose they could invade to take over the real estate. They could invade to enslave us (probably more for cultural reasons than practical ones, an interstellar civilization is probably advanced enough not to need our slave labor). They could assimilate us in to their empire "for our own good". They could fear our eventual potential and wipe us out to avoid it. But bulk materials and energy? Nothing here (except for products of life which they could probably synthesize from widely available resources), that they can't get in greater quantities for less effort, elsewhere. |
