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Re: st: Re: rank regression
From
John Antonakis <[email protected]>
To
[email protected]
Subject
Re: st: Re: rank regression
Date
Mon, 24 Feb 2014 08:05:51 +0100
If the dependent variable is a rank, where rank ordering does not seem
to be roughly equidistant, then they should have used an ordinal probit
or logisit estimator: -oprobit- or -ologisit-. If the independent
variables are in the same boat (non equidistant), I would model them as
dummies.
Best,
J.
__________________________________________
John Antonakis
Professor of Organizational Behavior
Director, Ph.D. Program in Management
Faculty of Business and Economics
University of Lausanne
Internef #618
CH-1015 Lausanne-Dorigny
Switzerland
Tel ++41 (0)21 692-3438
Fax ++41 (0)21 692-3305
http://www.hec.unil.ch/people/jantonakis
Associate Editor:
The Leadership Quarterly
Organizational Research Methods
__________________________________________
On 24.02.2014 04:25, Joseph Coveney wrote:
Rochelle Zhang wrote:
a finance paper I was reading today uses rank regression , the author
states that they replace both the dependent variable and independent
variables by their respective ranks and evaluation the regression
using the ordinary least squares.
I searched "stata rank regression", and did not find anything. If you
have knowledge how to conduct such regression, please share.
--------------------------------------------------------------------------------
From your description, it sounds like the authors of the finance paper were just computing Spearman's correlation coefficient. See the Spearman section of the do-file's output below.
On the other hand, if there were two (or more) independent variables, then they might have been doing what I call "Koch's nonparametric ANCOVA". See the last section of the output below. You can read about it at this URL: https://circ.ahajournals.org/content/114/23/2528.full and the references cited there. Scroll down until you come to the section that is titled, "Extensions of the Rank Sum Test".
Joseph Coveney
. clear *
. set more off
. set seed `=date("2014-02-24", "YMD")'
. quietly set obs 10
. generate byte group = mod(_n, 2)
. generate double a = rnormal()
. generate double b = rnormal()
.
. *
. * Spearman's rho
. *
. egen double ar = rank(a)
. egen double br = rank(b)
. regress ar c.br
Source | SS df MS Number of obs = 10
-------------+------------------------------ F( 1, 8) = 0.64
Model | 6.13636364 1 6.13636364 Prob > F = 0.4458
Residual | 76.3636364 8 9.54545455 R-squared = 0.0744
-------------+------------------------------ Adj R-squared = -0.0413
Total | 82.5 9 9.16666667 Root MSE = 3.0896
------------------------------------------------------------------------------
ar | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
br | .2727273 .3401507 0.80 0.446 -.5116616 1.057116
_cons | 4 2.110579 1.90 0.095 -.8670049 8.867005
------------------------------------------------------------------------------
. test br
( 1) br = 0
F( 1, 8) = 0.64
Prob > F = 0.4458
. // or
. spearman a b
Number of obs = 10
Spearman's rho = 0.2727
Test of Ho: a and b are independent
Prob > |t| = 0.4458
.
. *
. * Koch's nonparametric ANCOVA
. *
. predict double residuals, residuals
. ttest residuals, by(group)
Two-sample t test with equal variances
------------------------------------------------------------------------------
Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval]
---------+--------------------------------------------------------------------
0 | 5 1.018182 1.601497 3.581057 -3.428287 5.464651
1 | 5 -1.018182 .8573455 1.917083 -3.398555 1.362191
---------+--------------------------------------------------------------------
combined | 10 0 .9211324 2.912876 -2.083746 2.083746
---------+--------------------------------------------------------------------
diff | 2.036364 1.816545 -2.152596 6.225323
------------------------------------------------------------------------------
diff = mean(0) - mean(1) t = 1.1210
Ho: diff = 0 degrees of freedom = 8
Ha: diff < 0 Ha: diff != 0 Ha: diff > 0
Pr(T < t) = 0.8526 Pr(|T| > |t|) = 0.2948 Pr(T > t) = 0.1474
. // or
. pwcorr residuals group, sig
| residu~s group
-------------+------------------
residuals | 1.0000
|
|
group | -0.3685 1.0000
| 0.2948
|
.
. exit
end of do-file
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