• Tryptaminev@lemm.ee
    link
    fedilink
    arrow-up
    3
    arrow-down
    1
    ·
    edit-2
    5 months ago

    Your math is poor a.f. And your argumentation doesn’t hold. The inflation rate is the relative change over a defined time-period. It is not a derivate. And a 10% interest rate p.a. corresponds to a .026 % interest rate per day. But that is still not the derivate. If we look at hours we are at a rate of .00109 %. And that is still not a derivate.

    So @[email protected] is absolutely right also for interest rates. If you look at arbitrarily small timeframes it will always become a very small number.

    • dragontamer@lemmy.world
      link
      fedilink
      English
      arrow-up
      1
      arrow-down
      2
      ·
      edit-2
      5 months ago

      The inflation rate is the relative change over a defined time-period. It is not a derivate.

      Have you taken Calculus? This is one of the most basic of Calculus subjects. https://en.wikipedia.org/wiki/Time_derivative

      Time derivatives are a key concept in physics. For example, for a changing position x its time derivative dx/dt is its velocity, and its second derivative with respect to time, d2x/dt2 is its acceleration. Even higher derivatives are sometimes also used: the third derivative of position with respect to time is known as the jerk. See motion graphs and derivatives.

      I know not everyone takes Calculus. But this is quite elementary if you’ve taken the subject. There should be no confusion here.


      Inflation is the change of price over the change of time. Or alternatively, Inflation describes the first derivative of price. What people care about however is the overall price, which unfortunately policy-makers can’t really control that well. We only have controls over the change-of-prices (ie: the derivative), not the actual direct price controls.

      EDIT: My note about “infinitely small intervals” is the basic limit definition of the Derivative. https://tutorial.math.lamar.edu/classes/calci/defnofderivative.aspx

      • Tryptaminev@lemm.ee
        link
        fedilink
        arrow-up
        3
        ·
        edit-2
        5 months ago

        The interest rate is commonly given p.a. so per year. So if you take a shorter time it becomes arbitrarily small. But to take acceleration as an example. If you have an acceleration of 1 m/s² it is a derivate. But if you take it as the acceleration over a year you get 31,536,000 m/year² which is also technically a derivate, but a completely nonsensical expression.

        And that was the joke @[email protected] made. And you showed why mathematicians don’t like it if economists want to brag about their math knowledge. Because you think your basic calculus qualifies you to be overly pedantic without showing real understanding of the concepts behind it.

        • dragontamer@lemmy.world
          link
          fedilink
          English
          arrow-up
          1
          arrow-down
          1
          ·
          edit-2
          5 months ago

          doesnt stop my can of sparkling water from doubling in price in the last few years just because you want to limit “inflation” changes to ‘12 months’

          You’re going the wrong direction yo to his original words. I don’t even know what you’re complaining about anymore. The original poster was trying to stretch time out to multiple years. My joke was that shorter-time frames is what is more accurate because that’s what mathematics / calculus has traditionally done.


          I’ve said my piece, and I stand by it. I’ll repeat it here.

          Prices are prices. If you want to complain about prices, then complain about prices. But we all know we aren’t going to do anything about prices. Furthermore: falling prices are utterly terrible for economies, so no one wants to force deflation.

          I’ve done many inflation topics over the last 5 years. I’m surprised at how utterly shit people around here on this topic are. I’d expected more of lemmy users to know the basics of this subject. But I do appreciate you trying to catch me on a technicality, however arbitrary it was… you’ve demonstrated that you’re at least at the Calculus level to me.