[davidiach]

And even fewer realize that a 2.1% growth rate is itself exponentially faster than a 2% growth rate.

If something grows by 2% per day, vs 2.1% per day, after a year the second one is >20x bigger.

[algorias]

What you say is true in principle, but your numbers are wrong. I got a rather less dramatic 50% difference after a year:

  >>> 1.02**365
  1377.4082919660768
  >>> 1.021**365
  1969.6808462403098
  >>>

[davidiach]

Thanks for the correction, I didn't actually do the math for that, just remembered something I've read a while back, but the numbers where different 20% vs 21%.

Apparently I don't understand exponential growth either cause I assumed a 5% difference scales linearly (as in the difference between 20% vs 21% growth rates for a given period should be the same as between 2% and 2.1%).

Silly me.

[hef19898]

But a good exmple showing why numbers are so important. A 50% difference is an order of magnitude away from a factor 20. Thing is, once out there the wrong factor 20 is impossible to correct.