Modern Econ has its roots in "the marginal revolution" and the marriage of Stats and Econ leading to "Econometrics".
Yes, but whenever I read Malthus or marx i find that these two individuals often tried to use math to explain their theory. What type of math were they using?
did he do anything with derivatives?
I think for Marx it may have been Calculus.
Actually I think for Marx and Malthus may have employed Calculus.
For Malthus it may have been to compare proportional growth rates of food and population. d'(t)/d(t) of two different variables with one another. You can simulate a lot of this in the Robinson Crusoe economy.
For Marx... not sure. He did write a book called the "Mathematical Manuscripts of Marx" and it was just AP Calc or Freshman Calc level.