Questions tagged [ecological-study]

"Studies of risk-modifying factors on health or other outcomes based on populations defined either geographically or temporally" (Wikipedia)

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Correlation Matrix or Covariance Matrix in PCA [duplicate]

I have 4 metrics, three of them measured on the scale 0 to 1, and one measured on the scale 0 to 6. When I stored my data, I converted the fourth one by dividing it by 10, so that I can get values ...
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Estimating proportion

In the context of an ecological study, I am trying to estimate the proportion of a certain mode of transmission on total incident cases of a disease (i.e. "x % of the incident cases transmitted by Z"),...
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Question about design choice of Enbrel RWE study

Statisticians in 2015 analyzed real world data, hundreds of thousands of medical insurance claims involving people with rheumatoid arthritis and other inflammatory diseases, according to the Pfizer ...
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36 views

Which tests can be used for variables that are non-normal, but have homogenous variances?

I am trying to compare the effect of two treatments (planting distance) on the growth of plants (multiple species), using the variable growth rate in diameter for multiple years. I have 4 sets of ...
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1answer
37 views

Which stats can test differences between two experiments?

I have an experiment to look at habitat preferences of beetles and the effect of competition. In the first test, a beetle is on his own in an arena and I measured the % of time he spends in each of ...
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1answer
3k views

What's the difference between an ecological study and a cross-sectional study?

What's the difference between an ecological study and a cross-sectional study? And could you provide an example?
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80 views

OLS difference between individual level and aggregate level estimates

I am new here, so please accept my apologies if this does not belong here. My question essentially concerns what appears to me a special case of the ecological fallacy. Consider a simple model that ...
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157 views

Can I use a correlation between between Gender Inequality Index and Crude divorce rate obtained from different countries?

If I have to find a link between Gender equality and Divorce rates, can I then use a correlation between between Gender Inequality Index and Crude divorce rate obtained from different countries? If ...
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1answer
94 views

Does the Mann-Whitney U-test need to be adjusted in twin studies?

I have data from 44 twin pairs (88 patients total) and they are split into group_A (n=50) and group_B (n=38). For each of the ...
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1answer
106 views

It is correct to use units other than individuals or samples on X axis of rarefaction curves?

The rarefaction curve is a very useful statistical tool for biodiversity analysis. It represents the number of species on Y axis, adjsted by individuals, samples (Gotelli & Graves,1996; Gotelli &...
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49 views

Is County-Level Aggregation Sufficient To Anonymize?

Is county-level aggregation sufficient to anonymize the data such as that found in the US Census or GSS?
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123 views

Example of danger of ecological correlation of rates?

Lots of textbooks and websites warn about drawing conclusions from "ecological correlations" which are defined as correlations between rates or averages. All the places I've looked at have used the ...
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Do ecological studies commonly use weights?

I'm working on an ecological study, where I've got 10 years of data for all 3000+ counties in the US. I'm interested in different perspectives on whether in a study like this one should weight the ...