Saturday, March 29, 2014

Angsioco's grammatical error regarding percentages: Comparison with Guttmacher Institute and Population Commission

Angsioco's Twitter posts dated 28 March 2014
Angsioco's Twitter posts dated 28 March 2014

In my previous post entitled, How numbers and statistics can lie: a response to Elizabeth Angsioco, I showed how Angsioco misinterpreted the statistics with her following statement:
  • "85 percent of respondents have gotten pregnant 1,933 times.
Twitter For Dummies
Twitter For Dummies
 Angsioco could have easily corrected her article by changing the wording of her statement into "1,933 is the sum of the number of pregnancies of each of the 528 respondents, [so that] the average number of pregnancies per woman in this group is 3.66 pregnancies" as I have suggested in my article.  Surprisingly, she still insisted on her own interpretation of her own words, as the screen grab of her Twitter account @bethangsioco dated 28 March shows:
  • "Accusing me of trying to make people believe that a woman can give birth almost 2k times is ridiculous.  Also, I ain't that dumb."
  • "It's absurd if u can even believe that I can make people think that a woman can give birth almost 2k times. It's actually funny."
If we assume that Angsioco did not intend to bloat the numbers, then I think this is a case wherein we need to review our use of the English language, especially in describing percentages.  

Inconceivable: A Woman's Triumph over Despair and Statistics
Inconceivable: A Woman's Triumph over Despair and Statistics
Let us look at three examples of sentence constructions involving the pattern "[number] percent of [group] have [something]", starting with Angsioco's statement:
  1. "85 percent of respondents have gotten pregnant 1,933 times." (Angsioco, Numbers Don't Lie, Manila Standard Today, 22 March 2014)
  2. "In 2008, there were 54 unintended pregnancies for every 1,000 women aged 15–44. In other words, about 5% of reproductive-age women have an unintended pregnancy each year." (Fact Sheet: Unintended Pregnancy in the United States by Guttmacher Institute) 
  3. "In the Philippines, 12 percent of adolescents aged 15-19 have experienced pre-marital sex.(Source: Zablan, Marquez and Laguna, 2003) (From: "World Population Day 2013 is focused on Adolescent Pregnancy" by the Philippine Commission on Population).  
In statement 2, there is only one unintended pregnancy (because of the article "an") after the word "have," even though there were 54 unintended pregnancies for every 1,000 women aged 15-44.  What follows after "have" refers to the characteristic possessed by the average woman in the group and not to that of the whole group.  If we follow Angsioco's sentence construction, then the independent clause should have been "about 5% of 1,000 reproductive-age women have 54 unintended pregnancies each year."

In statement 3, the phrase after "have" describes only the average adolescent aged 15-19 regarding her experience of pre-marital sex. If we follow Angsioco's sentence construction, then this sentence should have been "12 percent of adolescents aged 15-19 have experienced [several cases of] pre-marital sex."

On the other hand, if the sentence constructions of Guttmacher Institute and the Population Commission are correct, then what follows the "have" is the property of the average characteristic in the group, so that Angsioco's statement should be revised as follows:
  • "85 percent of respondents have gotten pregnant 3.66 times."
The reason for this is that there were 621 respondents and 85% of 621 is 528.  Since the sum of all pregnancies of each individual member of the 528 respondents is 1,933 pregnancies, then the pregnancy rate in this group is 1,933/528 =  3.66 pregnancies per woman.

How to Write a Sentence: And How to Read One
How to Write a Sentence: And How to Read One
So we are now faced with two choices:
  1. Angsioco's sentence construction is correct, while that of Guttmacher Institute and Population Commission are wrong
  2. Angsioco's sentence construction is wrong, while that of Guttmacher Institute and Population Commision are correct.
In either case, since Angsioco, Guttmacher Institute, and the Population Commission are all supporters of the RH Law, then the pro-RH Law groups will have to argue among themselves on whose grammar is correct.