23 November 2012

Causality 101


(In a statistical training we just attended on pooled and panel data analysis, our trainer Dr. Dennis Mapa, a statistician-economist reviewed John Stuart Mill's necessary conditions to establish causality or causal argument. Sans the mathematical proofs that sometimes rob us of the intuition , he so clearly summarized that TO ESTABLISH CAUSALITY, one has to establish that (1) the cause preceded the effect; (2) the cause was related to the effect; and (3) we can find no plausible alternative explanation for the effect other than the cause. He added that TO BE ABLE TO USE A RESULT FOR FORECASTING, one has to establish a fourth condition: (4) Past values of your outcome variable does not affect current values of your policy variable. And finally, TO BE ABLE TO ESTABLISH A POLICY EFFECT, one has to establish that the beta coefficient for that policy variable is not changing through time. 

While reality in empirical research is limited by resources--time, budget, willing subjects-- so that a "perfect data" is, most of the time never available and difficult to produce, the discussion reminded me to at least try my best to always have these conditions in mind from conceptualization to data gathering to data analyses to report-writing. Anyway, below is an exercise I found in the net on Mill's methods/conditions on causal arguments that drives the points very simply.)

 Exercise 20. Answer the following questions, and explain your answers.

i. Are causal arguments required to explain how the purported cause causes the effect?
ii. Are causal arguments required to show that the purported cause is the only thing that ever causes the effect?
iii. Are causal arguments required to show that the purported cause absolutely always causes the effect?
iv. Can a causal argument succeed without showing that the purported cause is at least sometimes correlated with the effect?
v. Can a causal argument be based on a "cause" that hasn't been previously proved to exist?
vi. Can a causal argument be based only on the fact that the "cause" is always absent whenever the effect is absent?
vii. Can a causal argument work if something else is just as strongly correlated with the effect as the purported cause?
viii. Can a causal argument be based on anecdotal evidence?
ix. Does the "cause" have to have a one-to-one correspondence with the effect?
x. Is "it's the only thing I can think of" ever a good causal argument?

Exercise 21. Answer the following questions, and explain your answers.

i. Is it possible to make a successful causal argument without any evidence of a correlation between the effect and the thing that’s supposed to be causing it?
ii. Is it possible to make a successful causal argument without providing an explanation of how the purported cause might cause the effect?
iii. Is it possible to make a successful causal argument without providing any evidence that the purported cause even exists?
iv. Is it possible to make a successful causal argument if it is proven that the purported cause sometimes happens without being followed by the effect?
v. Is it possible to make a successful causal argument based on a single incident?
vi. Is it possible to make a successful causal argument if it is proven that the effect sometimes happens even though the purported cause is not present?
vii. Is it possible to make a successful causal argument based only on the fact that no-one else can think of anything that could cause the effect?

Exercise answers:

20.
i. No.
ii. Nope.
iii. Nuh-ah!
iv. Well, no.
v. Good god, no! (oops, he can say it better next time-che)
vi. No way.
vii. No. Are you kidding?
viii. Noooooooo.
ix. Ha! No.
x. Don’t make me laugh!
(All answers are "no.")

21.
i. No.
ii. Yes.
iii. No.
iv. Yes.
v. No.
vi. Yes.
vii. No. 

(SOURCE:  Martin C. Young, 2009 see full article at http://www.madwizard.com/ctl_causal.htm)

16 November 2012

Thanksgiving for Chairo at 1





















14 November 2012

A treat for my sweet boys








(Photo taken by Khane)

4 October 2012

Chairo at 11 mos




Quotable quotes from the rice trade policy seminar

"Anyway, it is a postponement of the inevitable."-Roehlano Briones (on rice tarrification vs. QR)

"Let me be the husband that the pregnant wife curses."-Ramon Clarete (on rice trade liberalization)

19 September 2012

Tatalon-talon ang engine

While I was driving Khane to school,

Khane: Mama, ang kaya mo lang overtake-an ay iyung mababagal at maliliit?
Mama: Oo anak, at kahit maliliit kung mabilis hindi ko oovertake-an.
Khane: Tricycle, motor, bike lang mama?
Mama: Oo tsaka kuliglig. Alam mo ba iyung kuliglig?
Khane: Mama, ung tatalon-talon ang engine sa harap at 'kushuug'?
:) :) :)

12 September 2012

Let him that glorieth glory in this:

Jeremiah 9:23-24

English Standard Version (ESV)

23 Thus says the Lord: “Let not the wise man boast in his wisdom, let not the mighty man boast in his might, let not the rich man boast in his riches, 24 but let him who boasts boast in this, that he understands and knows me, that I am the Lord who practices steadfast love, justice, and righteousness in the earth. For in these things I delight, declares the Lord.”

New International Version (NIV)

23 This is what the Lord says:
“Let not the wise boast of their wisdom
    or the strong boast of their strength
    or the rich boast of their riches,
24 but let the one who boasts boast about this:
    that they have the understanding to know me,
that I am the Lord, who exercises kindness,
    justice and righteousness on earth,
    for in these I delight,”
declares the Lord.

 King James Version (KJV)

23 Thus saith the Lord, Let not the wise man glory in his wisdom, neither let the mighty man glory in his might, let not the rich man glory in his riches:
24 But let him that glorieth glory in this, that he understandeth and knoweth me, that I am the Lord which exercise lovingkindness, judgment, and righteousness, in the earth: for in these things I delight, saith the Lord.