1) Technically there is no “Nobel Prize” in Economics.
2) Economics is a “hard science” in that it is essentially applied mathematics. The prime difference between Economics and the physical sciences is that in Economics we study, essentially, human behavior through prices, etc. and attempt to make predictions on that behavior. Math don’t work so good when humans are in the equation.
In regards to the article, Paul Krugman gives economists a bad name. I prefer Friedman.