[ODP] Increasing inequality in general intelligence and socioeconomic status as a res
Is there any empirical data for SD trends over time? You cite a study of the IQ in 2003, but no cohort-based studies of changes in SD.

g should be italicized in a paper. "Authors" as a plural should not have an apostrophe (as on p. 4). "Gini" (as in "Gini coefficient") should be capitalized.
It's not all over the place. For reading and science, SDs tend to decrease over time. It's clearly different from the pattern displayed in figure 6. Although PISA is not intelligence test, I wasn't expecting this.
1) "Fifth, comparisons between full-siblings living together show that"

should be reared/raised together

2) "to calculate the composing of populations"

Composing? Rephrase.

3) "we show the out using step sizes of"

Show the outPUT?

4) "Adding two normal distributions together with different means always results in a greater SD."

Wouldn't the SDs of the distributions have to be similar for that to be true?

5) You should add some descriptive statistics on the countries of origin of the immigrant population in Denmark.

1) "Fifth, comparisons between full-siblings living together show that"

should be reared/raised together

Changed to "reared".

2) "to calculate the composing of populations"
Composing? Rephrase.

Changed to "to calculate the aggregation of populations".

3) "we show the out using step sizes of"
Show the outPUT?

Fixed.

4) "Adding two normal distributions together with different means always results in a greater SD."

Wouldn't the SDs of the distributions have to be similar for that to be true?

Changed to "Adding two equal sized, equal SD normal distributions together with different means always results in a greater SD.".

We have been trying to prove this theorem deductively, but it is not easy. We consulted some mathematicians who were also unable to prove it. It is easy to show by illustration of course.

5) You should add some descriptive statistics on the countries of origin of the immigrant population in Denmark.

I can add a table in the appendix with their relative size over select years. Is that what you desire? E.g. percent of the population by each country of origin 1980, 1985, 1990, 1995, 2000, 2005, 2010?

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New revision added: https://osf.io/dei73/, dated 14th Nov. 2014. #7

Delete the comma from the link
Introduction. Constant Danes population size could be due to lowered mortality due to increased lifespan. You should also plot number of deaths or death rate against year in figure 2.
Population t+1= Populationt+Naturalincreaset+Netmigrationt
Naturalincreaset= Birthst+Deathst
This model should be incorporated in the paper.
“The reason for the apparent paradox is that there is a constant conversion of people from the
’foreign origin’ category to the ’Danish origin’ category”
You cannot state this if you do not include the number of deaths in your demographic model.
Section 4.3. > I would like to see this tested on an existing population with long lasting and widespread migration history, such as the US. How did the SD in IQ or average height in the US change over the last 100 years or so? Is it higher than countries with more homogeneous ethnic background, such as Iceland or Finland?
For example we know the ethnic composition of White Americans (e.g. 25% German, 10 % Irish, etc.) and the average heights and SDs of the European countries from which they descend. This will enable you to test your model.
This seems to be another case of the reviewer wanting the paper to be about something other than it is. It is not reasonable to demand a new complex analysis of deaths for the simple claim that conversion of people from "foreign origin" to "Danish origin" is happening. This is plainly obvious from the definition. A child born to 1 genetic Dane and 1 foreign origin will be counted at 1 "Danish origin" in their data. That person would of course be 50% Danish genetically, but since s/he is counted as 1, it introduces error in estimates such as ours.

Yes, I agree. That's why I don't understand why you took the trouble of plotting birth rate. That way you set yourself up for elaborating more and doing complex modelling. If you offer half cake people will want the other half.
In my opinion you should keep it simple and just say that the conversion of people from foreign origin to Danish origin is happening introduced error in the estimate.Otherwise you'll shoot yourself in the foot.
Although I understand the basic idea of the article, I'm not even sure what your model depicted in figure 3 is trying to say. Is that a simulation study (in figure 3) ? Can you translate this passage here ? I don't understand it.

Briefly put, the model works by dividing normal distributions into intervals and finding the density of each interval. Normal distributions with different means will thus add differently to each interval, and each can be weighted by its size.

Consider the case where we want to model the merging of two equal sized populations with means of -.5 and .5. Suppose that we want to model it in the region -5 to 5. The effect of the step size is to increase the resolution and make the estimates from the intervals closer to the true normal distributions. Below, we show the out using step sizes of 2, 1, .5, and .1.

I have also never heard about "interval means" (in your R syntax).

And, some few other things :

Figure 3 appears in your article but not cited/mentioned in your text. At page 6, you write "Where x-bar is the mean value and xi is the i 'th value." You should also say that Σ is "sum of".

Finally, your graphs at figures 8-9 are pictures published in econometric papers by the usual group of economists who look at the trend in inequality (Piketty and co.). But are you sure you won't have problem with copyright or something ? In some books, it's common to read annotations (below the graphs) such as "reprinted with permission of xxx".
Ok.

About this, "Since we consider the no gains (100% heritability) implausible, we place our money on something akin to the weak gains model." I don't think what is written in parentheses is true. It could be that the absence of gain is consistent with <100% heritability if environmentality, for some reasons, keep the IQ levels constant. Some rGE (G-E correlation) theorists used that argument (although wrong in my opinion) to explain why compensatory educational intervention does not improve IQ.

And, finally, can you describe in your text how you make the four models presented in table 2 ?
Admitting that the g-relevant environment is not better in Denmark than lower scoring host countries, means the difference between host countries and DK is 100% heritable.

It's an unlikely assumption. Ok, environments among high IQ (developed) countries are probably not very different, and between-country environmental gap is large only if you compare developed and undeveloped countries. However, small environmental difference can generate small IQ gains/losses. How do you know that "the g-relevant environment is not better in Denmark than lower scoring host countries" ?

We applied these gains only to countries with an IQ lower than Denmark.

I would like you to give more information about the mean IQ (max. and min.) of these countries. How much lower ? Information about SD of IQ may also be useful.

In your figure 3, i noticed that the first graph displays two non-normal distribution. Both groups have skewed IQ distribution.

Fifth, comparisons between full-siblings reared together show that the higher IQ ones tend to do better in society. This cannot be attributed to shared environmental factors since these are shared by the siblings.

You can add Nedelec et al. (2012).

Nedelec, J. L., Schwartz, J. A., Connolly, E. J., & Beaver, K. M. (2012). Exploring the association between IQ and differential life outcomes: Results from a longitudinal sample of monozygotic twins. Temas em Psicologia, 20(1), 31-43.

It shows that non-shared environment has no predictivity. However, the direction of the correlations is more consistent with a conclusion of inconsistent finding than with a conclusion of null finding. They also do not correct for measurement errors, e.g., by using latent variable approach. So, you may or may not cite it.