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  • Help with nonlinear regression - updated post (based on comments on previous post)

    Hi all

    I did post about this couple of weeks earlier. Please accept my apologies for the lack of clarity and explanation in my previous post.

    I'll try explain what I am trying to achieve as best I can.

    I am trying to fit the following nonlinear regression model:

    excess_returns = alpha^tau + [(delta^tau) * (beta1*X)] + (beta2*V) + e

    whereby:

    1. X = an event dummy which equals 1 upon occurance of an event and 0 otherwise
    2. alpha^tau and delta^tau are scalars that are allowed to take on different values for each calendar year (2004, 2005....); with tau being equal to 1 on average
    3. V = volatility measure

    I am having difficulties defining (2) in my equation, i.e. allowing tau to vary according to calendar year.

    A part of my dataset is provided below. I have provided a case with 2 events (around 15 returns observations per year) for years 2004 and 2005.

    I have created the event dummy and event dummies accordingly.

    Code:
    * Example generated by -dataex-. To install: ssc install dataex
    clear
    input float(date yr) long category float(excess_returns daily_volatility evtdum)
    16120 2004 5 -.0041710553   .00610615 1
    16121 2004 .  -.002605169  .005672948 0
    16124 2004 . -.0027607314  .005107096 0
    16125 2004 .   -.00169663  .005328464 0
    16126 2004 .    .00398276 .0033022955 0
    16127 2004 .  .0010536329  .004524223 0
    16128 2004 . -3.87844e-06  .005174306 0
    16131 2004 .    .00954761   .00652635 0
    16132 2004 .  -.006000787  .004812117 0
    16133 2004 .   .001638213 .0045299074 0
    16134 2004 .    .00329056  .002689062 0
    16135 2004 .  .0016816463  .007512288 0
    16138 2004 .  -.008425278  .006753054 0
    16139 2004 .  -.005827282  .005510922 0
    16140 2004 .  -.014780972   .01003793 0
    16469 2005 5   .003082929   .00318898 1
    16470 2005 . -.0028594655  .003812133 0
    16471 2005 .    .01089252  .006926291 0
    16474 2005 .  -.001179559  .002438813 0
    16475 2005 .  .0003925901  .002471866 0
    16476 2005 .  -.008702259  .006162649 0
    16477 2005 .  .0041126176  .003623021 0
    16478 2005 .    .00681175  .007551926 0
    16481 2005 .  .0006066508  .001664312 0
    16482 2005 .   .003204334  .003437483 0
    16483 2005 . .00009175942  .003666668 0
    16484 2005 .  -.008044923  .005273449 0
    16485 2005 .  .0006092897  .002787331 0
    16489 2005 .   -.01470196  .009220046 0
    16490 2005 .     .0055017  .004728368 0
    end
    format %-td date
    label values category c
    label def c 5 "US Macro & Political", modify
    Would appreciate any help with the above.

    Thanks in advance for replying.
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