I'm currently tasked in my job to design a Prospect Theory (here CPT-)index as mentioned in Barberis, Mukherjee and Wang (2016): "Prospect Theory and Stock Returns: An Empirical Test", see https://nicholasbarberis.github.io/bmw17b.pdf
I wrote the CPT function in C# and got a bunch of stocks incl. their historical prices, which i fed into my analytical engine. While running the program, I noted that the ranking of high/low CPT (cumulative prospect theory) stocks varies wildly with the degree of risk sensitivity, loss aversion and the decision weighting parameter.
BMW (2016) used standard parameter values in their paper but didn't elaborate much on the sensitivity of their CPT-index wrt. the different feasible parameter settings.
My idea is now to circumvent the issue of finding the "right/plausible" CPT parameters and to "calibrate" the parameters used in my CPT-index using in-sample data wrt. the best fit as in BMW (2016) via gridsearch: I want to maximize the significance of the (negative) coefficient in my ts-regression. However, I doubt whether this is the right way to do things as it smells a bit like overfitting and p-hacking to me (although i don't try to increase the predicitive power of the CPT-index..).
All those econometricians among you: Is this a permissible way to get my prospect theory parameters and what might be the issues with this?
I appreciate your help and suggestions, I'm grateful for any comments Thomas
PS: This is not a homework or thesis task but something i need for my job.. PPS: Corrected the paper reference (wrong autor, It's Baolian Wang, not Wang Baolian as you refer to the familiy name first in China (my chinese wife standing next to me insists i clearify it here:-D )