Is economics a science based more on statistics (observations) rather than rigorous reasoning? The world is now more complicated than ever. We are all building upon the shoulders of our forerunners. We cannot understand where everything came from and how everything has evolved, and hence we don't understand how everything interacts. But the building blocks of the world today interact with each other intensively and sometimes unnoticeably. And clearly, it is hard to follow every lead to calculate every interaction's influence. I mention this because in macroeconomics many effects can cause secondary effects and these secondary effects may also cause tertiary effects, so it seems to me like an unending loop.

Thus it seems to me that in macroeconomics we use statistics to find associations and then try to explain certain associations using intuitive notions (maybe a dominant underlying reason) given the results. It seems to me that results in macroeconomics cannot be rigorously argued like the ones in mathematics or even physics. Rather these results are merely approximations learned from the past which are not confirmed each time like the laws in physics, let alone mathematical theorems.

So is what I am saying correct or is it simply that I do not understand macroeconomics enough?
At the very foundation of sciences like Physics, rest relations and properties that they just are, no explanation can be given, but they have been found directly or indirectly to continue to hold, or at least to change at an inconsequential rate compared to the time-span (or space-span) of humans.  

Moreover, although Physics laws are also idealizations of reality (and they hold under "normal circumstances", too, as regards for example temperature or pressure), it has been found that a) "normal circumstances" abound, b) these idealized versions suffer negligible variation in the real world for any of (or most) practical purposes and c) what happens under "special circumstances" is also stable, a complementary law in essence.

For Mathematics, the foundations are also arbitrary, but not being of this world but purely mental concepts, they can be whatever we define them to be -no reality will come crushing in to refute them (it is a different matter when we want to map abstract Mathematics to the real world).  

In the Social Sciences, to which Economics belongs, the foundations contain relations and properties that have been found to change over time and over space, at rates much higher than physical properties change, and certainly within the time-span and space-span of humans. Plus, the observed variation around their idealized formulation is much larger.  

This is what makes Social Sciences much more treacherous and harder than the Hard Sciences, and this is why progression towards more universally valid results is so much slower, or even, the arrival at a bouquet of results for which we will know with enough certainty to which observed relations do they correspond.


  "It seems to me that results in macroeconomics cannot be rigorously
  argued like the ones in mathematics or even physics."


Results in Economics can be fully rigorously argued, ever since Economics adopted mathematical symbolism to express itself. The issue is not with the process of argumentation, but with the premises one starts from.