Pseudo-economists use variables in the formulas they create.  This can’t be done.   As Murray Rothbard pointed out, these variables are “unmotivated.”  They can attempt to solve for the variable, but they can always change.  In fact, everything in that equation is a motivated variable.    It’s all uncertain and subject to change.  The only constant in human action is change.  The future will always be uncertain.

Change is inevitable.  This renders the equations that they make futile.  You can’t predict human action with a formula.  You would have to be a soulless automaton for the formula to have a chance to be correct.  They can put together this nonsense for data in the past, but they can’t for data that will appear in the future.  Attempting to predict the future with mathematics is the height of ignorance only reached by economists.

Every action involves time.  No human on Earth can be neutral in regard to the time an action takes.  Goods are more valuable sooner than later.  Two actions might yield the same good.  The action that requires the shortest amount of time and/or the lower expenditure of labor, will likely be chosen.  There might be a tradeoff between the two.  Likewise, payment for a good today is worth more than payments over the course of a year.

All things are scarce, even time.  Time must be economized as other scarce goods.  There is not an endless amount of time for the mortal man.  This is why the action with the shortest amount of time might be chosen.  Additionally, we don’t have an endless supply of health and vigor, which is why the action with the least amount of labor might be chosen.  The actor must make a decision based on the tradeoffs of each.

They’ll look at past data and put together a formula that fits that, then try to apply it to the future.  When that doesn’t work, they’ll put together a new formula and test again.  This gives them the opportunity to test endlessly.  All the while, harming you, sometimes severely.  Those who actually understand human action could tell you before that this would not work.  They do, often, but they’re ignored.  Learn for yourself.  Don’t blindly listen to psychopaths.

Reference

Ludwig von Mises; Human Action