An Overview of Population Projections—Methodological Concepts, International Data Availability, and Use Cases
Round 1
Reviewer 1 Report
The authors provide a very basic review of population projections / forecasts. While I found the article readable and covered most of the main topics, unfortunately, it not provide any new contributions to our thinking. The discussion about the distinction between 'projections' and 'forecasts' has been done so many times. Demographers gave up decades ago and now tend to treat the two interchangeably under the argument that official projections are made using plausible assumptions, therefore, can be treated as 'forecasts'. The advantages and complexities of probabilistic forecasts (including Bayesian) have also been discussed in depth in the literature. Further applying cohort component projections to other groups has also been covered extensively. In short, this review doesn't make any contributions to the literature that I can see. The real challenges these days are in small area projections, integrating administrative data, and treating migration inputs as a matrices of movements rather than vectors of net migration counts or rates -- these issues are not even mentioned.
Author Response
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Reviewer 2 Report
This research provides an overview of deterministic or stochastic modeling with their advantages and disadvantages. In doing this, the study makes the distinction between population forecasts, expected future population development and population projections, assumptions on how a population will develop in the future. This research then explores how governments can use these projections and forecasts.
Thanks for the opportunity to review this paper. This manuscript is well developed until section 4, Selected Areas of Application of Population Projections. This section then confuses the previous distinction between projections and forecasts. I agree that population projections are necessary for planning purposes. However, this planning will, in fact, influence the population projection. These are part of the assumptions that are in the projection model, even if they use historical trends. My experience suggests that many of these planning actors have aspirational goals, which become forecasts in the area of labor, housing, economic growth, public finance, and infrastructure development. The population projection, by its definition, has already directly or indirectly addressed these assumptions. My suggestion is to remove this section from the manuscript because it is not needed and only confuses an excellent contribution to this paper.
Author Response
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Reviewer 3 Report
I am not an expert on the topic of population projection. I cannot assess the completness of this paper. However, I found this paper very interesting. I would recommend it for publication.
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Round 2
Reviewer 1 Report
This review, although slightly better than the previous version, still does not contribute anything to the literature. Much of my original concerns raised concerning this paper still stand.
Author Response
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