[ODP] An update on the narrowing of the black-white gap in the Wordsum
2014-Sep-30, 12:25:47, (This post was last modified: 2014-Oct-03, 03:20:55 by Meng Hu.)
#1
[ODP] An update on the narrowing of the black-white gap in the Wordsum
An update on the secular narrowing of the black-white gap in the Wordsum vocabulary test (1974-2012)

Abstract

The aim of this article is to provide an update to Huang & Hauser (2001) study. I use the General Social Survey (GSS) to analyze the trend in the black-white difference in Wordsum scores by survey years and by cohorts. Tobit regression models show that the black-white difference diminishes over time by cohorts but just slightly by survey years. That is, the gap closing is mainly a cohort effect. The black-white narrowing may have ceased in the last cohorts and periods.

Keywords: IQ, black-white gap

(I have initially tried to attach .rar file that contains the .doc, pdf files as well as XLS but apparently that option is not available for me. Can Emil or Duxide help me with this ? That should prevent google from indexing non-published versions, I believe.)

EDIT.

The article has been uploaded to OSF as well.
https://osf.io/9tgmi/

And here's the link to the xls file.
https://osf.io/2w4h9/


Attached Files
.odt   An update on the secular narrowing of the black-white gap in the Wordsum vocabulary test (1974-2012).odt (Size: 101.29 KB / Downloads: 238)
.xls   An update on the secular narrowing of the black-white gap in the Wordsum vocabulary test (1974-2012) (Meng Hu 2014).xls (Size: 62 KB / Downloads: 194)
Reply
2014-Sep-30, 13:28:55,
#2
RE: [ODP] An update on the narrowing of the black-white gap in the Wordsum
Just upload the project files to http://osf.io/
Reply
2014-Sep-30, 14:53:55,
#3
RE: [ODP] An update on the narrowing of the black-white gap in the Wordsum
I cannot even open the paper because I am on holiday and my old netbook is not well equipped. So I just read the abstract. Genetic admixture with Caucasians has been steadily increasing and reached about 20% in the contemporary African American population but could you find statistics with an estimate of how Euro admixture has gone up over the last century? And maybe correlate it with cognitive gap closing? This of course wouldn't rule out the cultural explanation but would show that the environmental explanation is not the only one available.
Reply
2014-Sep-30, 20:32:05, (This post was last modified: 2014-Sep-30, 20:32:42 by Meng Hu.)
#4
RE: [ODP] An update on the narrowing of the black-white gap in the Wordsum
(2014-Sep-30, 14:53:55)Duxide Wrote: could you find statistics with an estimate of how Euro admixture has gone up over the last century? And maybe correlate it with cognitive gap closing?

In the GSS, there are two variables, racecen1 and racecen2 for first and second race mentioned. I guess if someone answers black for racecen1 and white for racecen2 he could be biracial. The problem is that racecen1 has modest sample size (17480) while the sample size of racecen2 is ridiculous (1033). And I do not even look at those who don't have wordsum data. So, in the GSS itself, it's just impossible to do that.

Of course, there may be other data, but I don't have those.
Reply
2014-Sep-30, 21:29:53,
#5
RE: [ODP] An update on the narrowing of the black-white gap in the Wordsum
MH,

If you upload the files to OSF as I proposed, Piffer would also be able to read them. OSF features in-browser reading of PDF files and other standard files, like spreadsheets.
Reply
2014-Oct-03, 13:51:06,
#6
Review
The code for STATA should be in an independent supplementary file, not the appendix. Copying code from PDF files does not work well.

Quote:Figure 1 shows that there is a strong ceiling effect
for the wordsum variable in the white sample.

Which subset of data is the figures based on? The text doesn't say and the ceiling effect is not similar over time.

Can you put the figures in the text near where they are mentioned instead of having them compiled in the end. Keeping the regression tables back there seems okay.

Overall paper seems okay. I'm not familiar with tobit regression, so I can't comment on that.
Reply
2014-Oct-06, 01:39:02, (This post was last modified: 2014-Oct-06, 01:39:29 by Meng Hu.)
#7
RE: [ODP] An update on the narrowing of the black-white gap in the Wordsum
In the article, figure 1 obviously shows the histogram for the sample of each racial groups (but excluding people aged 70+). In the section "limitation" it is said that in the white sample, the ceiling effect diminishes over time (when looking at each category of cohort6). I attach the pictures here.

The pictures (fig. 1-3) are too large. I can only put one by page. I can put fig 1 exactly where you ask, but for figures 2-3, it's more difficult to put them exactly where I want. That did not look good. That's why I put everything at the end of the article.

For the syntax, I know that lot of people will not even look at the supplementary files, and I want to show the syntax, this can encourage others to do so.

For tobit regression, I would recommend :

The Uses of Tobit Analysis (McDonald & Moffitt 1980)
Roncek, D. W. (1992). Learning more from tobit coefficients: Extending a comparative analysis of political protest. American Sociological Review, 503-507.
Introductory Econometrics: A Modern Approach (Jeffrey M. Wooldridge 2012; pages 596-601) (you can have it in libgen)

Besides, I have detected two errors.

Quote:Concerning the variable "sibs" there are two observations for which the number of siblings (55 and 68) shows a dramatic departure from all other respondents. I decided to filter them out. As for age variable, I decided to remove (set to missing data) people aged 70 or more.

Concerns about sample representativeness have sometimes been expressed. Hence, following the recommendations of Hauser & Huang (1999) I weight the data by the variable "weight" which is the interaction of the variables "wtssall" and "oversamp", although this will not change the results.1

It's not "set to missing" because I "dropped" the observations. Also, it's not Hauser & Huang (1999) because there is no 1999 paper. Only the 1996, 1998 (in Neisser's book on the Flynn effect), 2000 or the 2001. I will correct those mistakes later.

By the way, I have contacted Hauser, Huang, Lynn, Flynn, and Dickens, that is, those who have worked on the BW IQ changes over time. They responded quickly, and (almost) the same day (30 sept/1 oct). Lynn said it's interesting. Huang said that their analysis needed an update, and he thanked me for doing so (and hoped the best for my publication). Flynn said it looks fascinating, and we must keep in touch. So, no one has really commented the article. I will try to email other people whose work is close to that topic. I think it's important to have the opinions from scholars.


Attached Files Thumbnail(s)
       
Reply
2014-Oct-06, 02:23:09,
#8
Review 1.1
MH Wrote:In the article, figure 1 obviously shows the histogram for the sample of each racial groups (but excluding people aged 70+). In the section "limitation" it is said that in the white sample, the ceiling effect diminishes over time (when looking at each category of cohort6). I attach the pictures here.

I mean, which year? All years combined?

Quote: The pictures (fig. 1-3) are too large. I can only put one by page. I can put fig 1 exactly where you ask, but for figures 2-3, it's more difficult to put them exactly where I want. That did not look good. That's why I put everything at the end of the article.

Just shrink them a bit so they aren't too large. They don't need to be that large. Having figures in the end of the article is bad since it interrupts reading flow (readers have to stop up, scroll to the end and read the figures, then jump back to the page with the relevant text).

Quote: For the syntax, I know that lot of people will not even look at the supplementary files, and I want to show the syntax, this can encourage others to do so.

Most readers will not read the code in the appendix either, and most readers don't use STATA and even those who do are often not familiar with complex syntax. I maintain that code should be in a supplementary file.

Quote:For tobit regression, I would recommend :

The Uses of Tobit Analysis (McDonald & Moffitt 1980)
Roncek, D. W. (1992). Learning more from tobit coefficients: Extending a comparative analysis of political protest. American Sociological Review, 503-507.
Introductory Econometrics: A Modern Approach (Jeffrey M. Wooldridge 2012; pages 596-601) (you can have it in libgen)

Thank you. I will look into the last reference.

Quote: By the way, I have contacted Hauser, Huang, Lynn, Flynn, and Dickens, that is, those who have worked on the BW IQ changes over time. They responded quickly, and (almost) the same day (30 sept/1 oct). Lynn said it's interesting. Huang said that their analysis needed an update, and he thanked me for doing so (and hoped the best for my publication). Flynn said it looks fascinating, and we must keep in touch. So, no one has really commented the article. I will try to email other people whose work is close to that topic. I think it's important to have the opinions from scholars.

I agree. Contacting relevant scholars is a good idea.
Reply
2014-Oct-06, 03:14:22, (This post was last modified: 2014-Oct-06, 03:18:20 by Meng Hu.)
#9
RE: [ODP] An update on the narrowing of the black-white gap in the Wordsum
The histograms are for all years combined. This is obvious since in the "limitation" I said the pattern looks different when we look at specific periods. I will however modify the sentence as follows "Figure 1 plots the histogram of wordsum for all years combined. It shows that there is a strong ceiling effect for the wordsum variable in the white sample.". Would it be ok ?

As for the size of the pictures, I did not ask that big, it's just how Stata has generated them, and i just saved them as png. I will try to reduce the size of the pictures without deteriorating the quality. However, I maintain it would not be possible to put the tables (notably the regressions) where you want me to put them. As you can see, their size is so large that you need (almost) an entire page. That's one of the reason why I put everything at the end. If you want, however, I will put the pictures where you think they should.

For the syntax, i will think about it, because I'm convinced it's beneficial. Of course, most won't care about it, but those who want to go into the details and are familiar with the software (unfortunately, R works badly for me, which is why I decided to use Stata instead) can see it. I have the feeling it's less likely they will examine my syntax if it's only displayed in the supplementary file. They won't bother to go here at OP forums, check the files, etc. That's what I'm afraid about.
Reply
2014-Oct-06, 03:48:11,
#10
RE: [ODP] An update on the narrowing of the black-white gap in the Wordsum
Some more comments.

MH Wrote:The histograms are for all years combined. This is obvious since in the "limitation" I said the pattern looks different when we look at specific periods. I will however modify the sentence as follows "Figure 1 plots the histogram of wordsum for all years combined. It shows that there is a strong ceiling effect for the wordsum variable in the white sample.". Would it be ok ?

It wasn't obvious to me. You should probably add it to the figure caption too.

Quote: As for the size of the pictures, I did not ask that big, it's just how Stata has generated them, and i just saved them as png. I will try to reduce the size of the pictures without deteriorating the quality. However, I maintain it would not be possible to put the tables (notably the regressions) where you want me to put them. As you can see, their size is so large that you need (almost) an entire page. That's one of the reason why I put everything at the end. If you want, however, I will put the pictures where you think they should.

I didn't say to move the regression tables I wrote "Keeping the regression tables back there seems okay.". You can easily resize the figures using whichever program you use to write in.

Quote: For the syntax, i will think about it, because I'm convinced it's beneficial. Of course, most won't care about it, but those who want to go into the details and are familiar with the software (unfortunately, R works badly for me, which is why I decided to use Stata instead) can see it. I have the feelin it's less likely they will examine my syntax if it's only in the supplementary file. They won't bother to go here at OP forums, check the files, etc. That's what I'm afraid about.

I think most readers, say 95%, will not examine the STATA syntax no matter where you put them. Those who want to will likely examine it no matter where you put it. You can add a link to the OSF repository in the paper, so they don't need to go to OP forums for the supplementary files.

-

I found another error:
Quote:I build four models. For model 1, I use cohort (or survey year), race, and the interaction of race with cohort (or survey year). For model 2, I add age and gender variables. For model 3, I add the log of real family income (realinc), degree (degree) and years of school completed (educ), and region of residence at age 16 (reg16). For model 3, I add the number of siblings (sibs) as well as "type of place lived at age 16" (res16) and "living with parents at age 16" (family16).

This should be model 4.

-

Quote:The variable race "bw1" has a value of 0 for blacks and 1 for whites. Since the year 2000, the GSS begins to ask whether the respondent is hispanic or not. 5 For respondents in survey year 2000+ I have only included the respondents who declared not being hispanic (see appendix). The variable year has values going from 1972 to 2012. The variable cohort has values going from 1883 to 1994. The variable sex has the following values; male=1, female=2. The variable age has values going from 18 to 89. The variable degree has the following values; 0=lower than high school, 1=high school, 2=junior college, 3=bachelor, 4=graduate. The variable educ has values going from 0 to 20. The variable realinc has values going from 245 to 162607, and the respective numbers for log income are 5.5 and 11.99. The variable reg16 has the following values; 0=Foreign, 1=New England, 2=Middle Atlantic, 3=East North Central, 4=West North Central, 5=South Atlantic, 6=East South Atlantic, 7=West South Atlantic, 8=Mountain, 9=Pacific. The variable res16 has the following values; 1= in open country but not on a farm, 2=on a farm, 3=town lower than 50,000, 4=50,000 to 250,000, 5=in a suburb near a big city, 6=city greater than 250,000. The variable family16 has the following values; 0=other arrangement with relatives (e.g., aunt, uncle, grandparents), 1=mother & father, 2=father & stepmother, 3=mother & stepfather, 4=father, 5=mother, 6=male relative, 7=female relative, 8=male & female relatives. The variable sibs has values going from 0 to 37 (apart from two apparent outliers).

Why do you mention the range of numerical variables, and all the possible values of nominal variables?

-

It is unclear how the nominal variables are used in the regression models. Hopefully you have not used them as continuous variables, as that makes no sense at all. Reg16 (region lived) and family16 are clearly not even quasi-continuous variables. Regression on that as they were is clearly nonsense. Res16 is quasi-continuous, so regression with it is okay.

-

Quote:which means the gap has been reduced by an half

-

Quote:stronger gain over time in the model 2

-

Quote:It is merely a vocabulary test, and its reliability is not high (0.71).

As far as I can tell, you use the internal consistency value (cronbach's alpha presumably). This is not optimal for adjusting for measurement error since it doesn't correct for transient error. See Hunter and Schmidt (2004, p. 99). The real reliability is probably somewhat lower.

-

Quote:The wordsum gap has been reduced by approximately 40% or 50% but this is still coherent with their idea that the black-white IQ gap is (at least) 50% genetic and 50% environmental.

This should be "consistent" I think.

-

Quote:The supplementary files are made available at http://openpsych.net/forum/index.php.

You should link to the specific thread (http://www.openpsych.net/forum/showthread.php?tid=168). You should also link to the OSF repository with the supplementary files.

Ref
Hunter, J. E., & Schmidt, F. L. (Eds.). (2004). Methods of meta-analysis: Correcting error and bias in research findings. Sage.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)