Science topic

Population Projection - Science topic

Explore the latest questions and answers in Population Projection, and find Population Projection experts.
Questions related to Population Projection
  • asked a question related to Population Projection
Question
2 answers
I have amassed decades long data on bird populations and need help in calculating their population trends. There is a great bulk of research published worldwide where a variety of statistical packages (e.g TrendSpotter, rTrim here) were used to index population trends, however, I found none that would do this job using Python. While I have a profficient Python developer, the latter is having hard time deciding on the choice of appropriate statistical methods that could be used to analyse data. Anyone can help?
Relevant answer
Answer
thank you for your feedback
  • asked a question related to Population Projection
Question
7 answers
I'm trying to find research on wildlife population estimation of a species in which individuals cannot be differentiated from each other. We have used Mark-recapture to estimate population size, now we're wanting to use other methods to verify our findings.
Being a dense vegetation, camera trapping is proving to be difficult and so is walking transects.
Can you suggest other methods by which population estimation can be done?
Relevant answer
Answer
We used CT in agricultural fields and setasides/game fields to count small game species and meso predators.
In front of the CT we did cut (in accordance with the farmers) a "window", a small clearance of 5x5m.
I recommend to read the several publications/guidances of ENETWILD.
  • asked a question related to Population Projection
Question
4 answers
Hello everyone, I am working on understanding the relationship between higher education and economic growth of India for which I am not getting data on GER from 1980 to 2000. Though, I have access to the total number of students enrolled but lacking the data on population projection for the age group 18-23 which I can use to calculate GER.
It would mean a lot if you may help me out with this. Anyone who has worked on the same variables please share your response.
Thank you!
Relevant answer
Answer
These population statistics can be obtained from Indian Statistical Institute (ISI) Kolkotta
Ministry of Education or Ministry of Human Resources, New Delhi might have the population data as you need.
  • asked a question related to Population Projection
Question
2 answers
Can you suggest any test that shows the sufficiency of a estimated value of a parameter from sample data? It is needed for one of my project that aims to estimate a population parameter.
Relevant answer
Answer
The suggestion indicates the hypothesis testing(mostly same), And it needs prior information, that whether the mean is equal to some value. Does the significance test of the coefficient work in this case?
  • asked a question related to Population Projection
Question
1 answer
I'm interested in doing a population projection of depression based on survey data. Are there any good articles that I could refer to in terms of methodology for such an analysis?
Relevant answer
Answer
Sounds like a question to be answered by a review of relevant literature. Best, D. Booth
  • asked a question related to Population Projection
Question
4 answers
Hi all I'm a final year student and studying about the relationship between ageing population and welfare effect. Though I looked for many articles still couldn't find proper econometrics based article to follow as my based study. If anyone interest on this topic or know about econometrics analysis with ageing population and welfare effect, please send me. Your favor is highly appreciated for my further studies. Thank You.
Relevant answer
Answer
Altough not exactly related to your research question, you may find Acemoglu & Restrepo (2017) useful as a first reference. You can check the paper here https://www.nber.org/papers/w23077
  • asked a question related to Population Projection
Question
6 answers
The idea comes from reading World Steel reports. The reports suggest that their current sustainability is going well in terms of reducing co2 emissions, recycling scrap metals and find renewable energy through wind turbines.
However, I'm curious that as the population is estimated to grow from 7 billion to 9 billion in 2050 there will be an increasing demand of steels for infrastructures, automobiles and other everyday essentials. This means the steel industry have to increase their production effort but that also means potentially increase the emissions as well. In terms of recycling as well, I expect there would be less as the industry would find a method of producing less scrap as the output.
Let me know what you think. Thank you
Relevant answer
Answer
Imed Miraoui yes I believe in the foreseeable future steel industry would still be polluting as much even though they have taken many steps in advancing technologies
Sjoerd van Acht and Yehia F. Khalil thank you for the recommendation. would you happen to have the article that you could pass on to me? It would be much appreciated
  • asked a question related to Population Projection
Question
4 answers
I want to know all available rigorous population estimation methods to assess the population of crocodiles, particularly Gharial crocodiles in their natural habitat. I also want to know if DISTANCE sampling works for Gharial crocodiles.
  • asked a question related to Population Projection
Question
6 answers
Does anyone guide me the articles or research for the population estimates of crocodiles through using camera traps data? Any guidance would be greatly appreciated!
Relevant answer
Answer
If you can uniquely identify your animals in the images, then there is a large body of literature on spatially explicit capture recapture which provides a solid framework for estimating animal density (in a spatially explicit way, potentially as a function of additional covariates) - The following reference provided a good soft introduction to the topic
Borchers, D. L. 2012 A non-technical overview of spatially explicit capture-recapture models Journal of Ornithology, 152 , 435-444
and this second one (is one of many examples that) provides details about camera trap studies:
Tobler, M. W. & Powell, G. V. 2013
Estimating jaguar densities with camera traps: Problems with current designs and recommendations for future studies Biological Conservation, , 159 , 109-118
This will work for crocodiles or any other species that can be uniquely identifianble from the photos. A diferent approach would be using distance sampling related approaches, and those are described here for camera traps:
Howe, E. J.; Buckland, S. T.; Després-Einspenner, M.-L. & Kühl, H. S. 2017.
Distance sampling with camera traps Methods in Ecology and Evolution, 2017
Finally, I don't know the deatils about this one, but the title suggest it might be what you need if individuals can't be identified uniquely - this will possible require some strong assumptions
Nakashima, Y.; Fukasawa, K. & Samejima, H. 2017
Estimating animal density without individual recognition using information derivable exclusively from camera traps Journal of Applied Ecology,
Hope it helps!
  • asked a question related to Population Projection
Question
13 answers
The past population estimates and existing data demonstrate that world population continued to grow since its origin to date. Extremely high rate of growth has been observed during the second half of 20th century along with medical and green revolutions. World population data sheets and other data sources tell that 80 to 90 million individuals are added to the global population every year increasing pressure on resources. Consequently, environmental, economic, social, political, demographic, and biological problems are also increasing and in some cases are appearing in new forms. On the other side, world communities, specifically more developed countries claim that they are taking several measures to overcome these issues. Here the question arises that in the prevalence of such kind of situation where population is augmenting rapidly, environmental degradation is at its apex and resources are already in pressure, is it possible to overcome these problems?
Relevant answer
Answer
Dear Khan,
The earth has and will always have enough "for everyone’s need but not for everyone’s greed". Therefore, the question is not about overpopulation but it has more to do with over-consumption and overproduction. It seems that for those with privilege it is easy to talk about overpopulation (human beings as if they were undesirable) and a few billions too many. Yet, those who have less in the world are the ones who exploit resources the least and conserve biodiversity the most. Unfortunately, the world's hunger is the results of wars and conflicts, not because of population growth. There is hunger and yet the amount of wasted food per year can feed the world four times over. Those who insist on talking about overpopulation are only finding a way to blame others and to divert attention away from greed and planetary vandalism that destroy our natural resources and take away what little is left from the 'have-nots'.
This is what they say: "There is overpopulation and therefore there are not enough resources for everybody." The eyes of some immediately turn to the growing populations in emerging and developing nations. Yes, there is population growth but it is not unsustainable if the wars and global mega-corruption will stop. In Japan and the West there is low birth rate; Russia is such a big country with less than 160 million people, and so on. Therefore, when people talk about overpopulation, they are referring to the others (those they deem undesirable).
It is easy to fall into the trap of going along with this narrative when they use mind games through imagery to suggest that the poor are giving birth to too many children even though there is not enough food to feed them and there are many diseases, too.
Consider this. Where there is industrialization and opportunities for all, birth rate tends to be low. Even in developing nations, the middle and upper middle classes have fewer children. It must be noted, however, that with or without food the privileged don’t like the poor anyway.
Solutions:
- Arrest greed, over-consumption and overproduction and don’t steal from the have-nots.
- Good nutrition can already solve most of global health problems – Waste not, want not!!.
- Let’s create opportunities for all so that girls can aspire to be anything they want to be - after college and Master’s or a possibility to learn a trade, no one has time for ten children per family. When girls have opportunities to go to college just like their male counterparts, they tend to also want to become professors, doctors, engineers, pilots, entrepreneurs. etc., because they can.
- Men should take responsibility for family planning: when women are left bereft of educational/vocational opportunities, men use them as breeding machines. Women don’t make the children all by themselves - and no child should suffer any indignation of being seen as the one who arrived in the world as one child too many.
Just my two cents.
Samberg, L. (2018). ‘World Hunger Is Increasing, Thanks to Wars and Climate Change’ Scientific American, October 18, 2017, available at: https://www.scientificamerican.com/article/world-hunger-is-increasing-thanks-to-wars-and-climate-change/ (accessed 12 September 2018)
World Hunger Is Increasing, Thanks to Wars and Climate ...
Scientific American is the essential guide to the most awe-inspiring advances in science and technology, explaining how they change our understanding of the world and shape our lives.
Deen, T. (2018). 'Food Waste Enough to Feed World’s Hungry Four Times Over', Inter Press Service, available at: http://www.ipsnews.net/2018/05/food-waste-enough-feed-worlds-hungry-four-times/ (accessed 3 June 2018).
  • asked a question related to Population Projection
Question
3 answers
I want to forecast Indonesian population with R. but it is difficult to run the program available on Web. I do learn from
but it do not work.
thank you very much
Relevant answer
Answer
Than you brother Robert Tolan.
  • asked a question related to Population Projection
Question
7 answers
Hi Im working with an ecological impact assessment on several bird species coupled to a high quality wetland habitat, threatened by significant exposure to traffic noise in the future. Regulatory framework will not allow a significant threat to "local favourable conservation status". Most birds in the area are migrating. challenge one is to define local populations. Many migrating birds keep returning to the same spot. We also have the development of subspecies. But how to define a specific geographical area for a species with no dispersal limit is, well, tricky.. challenge two is to define a minimum viable (local) population. I have population estimates for regions and country (with ranges). I also have spontaneously reported breeding data for last year and this year so far. I can list threats but not quantify any (maybe one threat).. Any ideas? I belive my task at hand is worthy of a research application, but I have couple of weeks...=) any help is appreciated (and the birds say thanks too..)
Relevant answer
Answer
Ok
well, it was worth a shot. noise is the threat that will bring this highway to the trials. The wetland will be 99% intact. The EA process is fine, but the fact that these questions always are left with a “best guess” bothers me, especially while there are so many models out there in the research community. Noise I perhaps a debated topic, but if you ask me, there is no question about whether Or not it has a sigonificant effect on avian communities.
i guess I’ll tackle it from a habitat availability approach then. the % habitat (maybe quality weighted) contribution of the wetland in question To the total availability in an area.
  • asked a question related to Population Projection
Question
8 answers
The human microbiota/ normal flora comprises the populations of microbial species that live on or in the human body. The biggest populations of microbe reside in the gastrointestinal tract. Evidences showed that the gut is the epicentre of antibiotic resistance. How these microbial population (that are estimated to be over 1,000 different species) contribute for antimicrobial resistance?
Relevant answer
Answer
Antimicrobial resistance is multi-factorial. Sub-optimal exposure to antimicrobial, gene transfer (both horizontal and vertical), spontaneous mutation are among the many. When there is frequent infection, there will be exposure to broad spectrum antimicrobials which will result in selection pressure in which resistant strains are selected. These strains will constantly evolve and result in gene transfer, both horizontal and vertical. The spontaneous mutation also contribute to the emergence of resistance.
  • asked a question related to Population Projection
Question
5 answers
I've been monitoring population trends of a threatened bird species in a developing country. My protocol uses numbers of breeding adults (not juveniles) to assess long-term population trends. My local colleagues are asking me why juveniles are not included in the population assessments. I know that only counting adult breeders is common protocol for many wildlife population studies, mainly because the adult population is more stable and less susceptible to short-term population fluctuations due to high juvenile mortality rates. However, I can't seem to find good references that specifically address this. Can anyone help me out with some references? Thanks in advance!
Relevant answer
Answer
As suggested, juveniles often aren't included because they don't directly contribute to population growth until they reach adulthood and breed. An individual that doesn't breed doesn't affect the population's future.
It's also important to note that different methods are usually required to sample different life stages. Juveniles are often too small to be caught and marked, are less mobile and thus less likely to be caught, or aren't detectable by methods used to find adults such as call/song surveys for birds.
The importance of juvenile vs adult survival is a whole sub-field - check out this paper and the sources it cites, particularly Sandercock et al and Wilson and Martin, which address birds.
  • asked a question related to Population Projection
Question
5 answers
ARIMA models, from what I know, are atheoretical models in the sense that they generally don't provide us with meaningful economic interpretation of why a process is behaving the way it does.
However in population forecasting, can ARIMA models be interpreted in a meaningful way?
i.e.
  • can AR(1) process can be interpreted as: "population growth in period t is a function of population in period t−1"
  • can MA(1)process can be interpreted as: "population growth in period t is a function of some policy or ongoing event (a country's policy on immigration or emigration) which has occurred in t−1"
Relevant answer
Answer
Hello Jacob
I am not a time series expert, but I have used them in my forecasting work. You ask two questions:
  • can AR(1) process can be interpreted as: "population growth in period t is a function of population in period t−1"
I would not expect this to be the case, as there is no reason why population size should influence population growth.
  • can MA(1)process can be interpreted as: "population growth in period t is a function of some policy or ongoing event (a country's policy on immigration or emigration) which has occurred in t−1"
As a direct effect, a change of policy in period t-1 can be expected to also affect period t. However, a change of policy is not specifically contained in the population data for period t-1. Knowledge of the policy is additional information, which would have to be explicitly incorporated in the model. A substantial change in population size in period t-1 could be temporary (a migration event or change of rules that affects the pace of migrant acceptances - i.e. a tempo effect); this would be noise or could also be modelled by a time-specific dummy variable. So, I would answer 'no': as in economics, time series models involving only one step are atheoretical in population forecasting. However, it may be the case that large-scale in-migration of young adults in period t-1 generates additional population growth in a subsequent range of years through childbearing and the in-migration of fiances, spouses, children and other dependents, and this may possibly be modelled by time series, though forecasting would involve high uncertainty. It may be possible to establish more meaningful interpretations of population size with lags of a generation or so, for obvious reasons, but the age range of childbearing (even in low fertility populations) would weaken the association.
  • asked a question related to Population Projection
Question
1 answer
Capture-recapture (CR) methods are usually used to estimate population size of newts with natural marks. Using CR assume that the population is closed and that capture probability of individuals is constant during all sampling events. It has been highlighted that during a single breeding season, individuals are moving from ponds to ponds and that the number of captures is correlated with lunar cycles (Deeming 2008 and 2009, Kopecky 2010).
In your opinion, can we assume trustfully (enough) that moving individuals do not change the proportion of marked/unmarked individuals (i.e. marked and unmarked individuals are likely to move equally)?
Can we assume trustfully (enough) that caught individuals are not learning to avoid traps between sampling events?    
Thanks in advance for your opinions.
Regards,
Xavier 
Relevant answer
Answer
Hi Xavier,
I’m not an expert in newts, but I can imaging this paper could be interesting for you, and maybe you can find some answer for your questions. Look for the supplementary materials as well. Regarding your question about the behaviour response to capture, is easy to take it in account and use the appropiate model.
Best,
Jose
Sutherland, C. et al., 2016. Spatial Capture-Recapture: A Promising Method for Analyzing Data Collected Using Artificial Cover Objects. Herpetologica, 72(1), pp.000–000. Available at: http://www.hljournals.org/doi/abs/10.1655/HERPETOLOGICA-D-15-00027.
  • asked a question related to Population Projection
Question
5 answers
In the last 117 years the population of the US has only once declined against a steady background of population growth.  The world was hit by a massive influenza pandemic during that period but could that alone have accounted for this anomaly or was there another factor operating
July 1, 1919        104,514,000          1,306,000              1.26 
July 1, 1918        103,208,000            -60,000               -0.06 
July 1, 1917        103,268,000          1,307,000              1.27
Relevant answer
Answer
Barry,
I think that the July 1, 1918 U.S. population number is unreliable. Prior to 1940 the U.S. Census Bureau did not count U.S. citizens that were stationed overseas in the military. Since over 4 million U.S. soldiers were mobilized between August of 1917 and the summer of 1918 the U.S. Census Bureau had to estimate how many were overseas versus living but not counted in the States. I'd say that the margin of error probably covers that supposed decrease.
There also could have been a decrease in births in due to an immediate anticipation of U.S. involvement in the war. While 1917 looks like a negative growth, there was a substantial decrease in population growth during the Great Depression. It was only after the economy crossed the threshold of where it was at the time of the start of the depression in 1929 that the population continued its more regular trend. Interestingly, from an historic perspective, there was an increase in the U.S. birth rate in 1940 that continued through World War II. This increase in U.S. population growth probably consisted of wartime babies in families that were recovering from the Great Depression and had elected not to have children due to the economic conditions at the time.
JAG
  • asked a question related to Population Projection
Question
5 answers
I'm doing a master on moose populations estimations with a citizen science approch.
I want to simulate a hunter and a moose population (of known size) in the same landscape, "make them meet", and see how the abundance estimations are biaised depending of the proportion of "cheaters" (hunters who don't say the right number of moose seen).
I explored the SELES and RAMAS/GIS softwares, but I'm not sure they are appropriate tools to simulate two animal populations movements in a static landscape.
Relevant answer
Answer
InsightMaker would work. It is very easy to use.
  • asked a question related to Population Projection
Question
2 answers
Scholars of Demography
Relevant answer
Answer
Professor Dr.N.Audinarayana is a famous Demographer, he wrote many books about Population projection, dynamics etc.  Try to contact directly his mail ID: audinarayana.bu@gmail.com
  • asked a question related to Population Projection
Question
4 answers
I am conducting genotypic data analysis for Association Mapping. I have 94 diverse accessions; however 2 genotypes have over 80% of missing marker data. Should I include those two genotypes in the population structure analysis and determine the optimum k?
I have completed twice population structure analysis using both all of the 94 genotypes and 92 genotypes (removed those two genotypes with over 80% of missing marker data). However, the optimum k from two methods is the same based on Structure Harvester. I don’t know if I should use all 94 genotypes or 92 genotypes for the further analysis?
Thank you!
Relevant answer
Answer
Yunfei, it depends on what is your further analysis. As you said, you obtained the same optimum k with or without these two genotypes. Hence, you may discard their informativeness (certainly they don't contribute much to the total informativeness, with more than 80% missing data). Otherwise, if the individuals are highly valuable for further analysis, you may keep them in the data set.
  • asked a question related to Population Projection
Question
7 answers
Due to the different sampling weights, I have concerns. I have included some background info for context and questions are at the bottom.
ISSUE--Developing a database: Individual-level collision records data will be merged with community characteristics gathered from several data sources (Census, population-based surveys, other individual-level data).
Population-based survey data have different population sampling weights.
All 4 datasets will be linked to the collision data using a geographic variable contained within each dataset.
DATASETS---
Individual-level Collision Data (linking variable=drilled down geographic variable which can be modified for ease of linking to different geographic levels)
+ Census data
+ County-level population-based survey #1 (weighted at the county level & has zip code)
+ County-level population-based survey #2 (weighted at the county level & has zip code)
QUESTIONS:
1) If the appropriate sampling weights are applied to the population surveys, is it allowable to link them to the collision data and other datasets?
2) The population survey data are representative of the County. However, we would like to present data at a more granular level (ex: census tract, planning area, etc.).
  • Is there a methodological approach to accomplish this?
Thank you!
Relevant answer
Answer
You can use a multilevel model to analyze the point data at level 1 and the county data at level 2 simultaneously - it is possible to use survey weights in such models see
It is  important to use such an approach - one reason is that there will be many more points than counties and the standard errors of the effect of variables at each level wil lneed to be calculated appropriately.
Inferring from counties to census tracts: there is a large literature on 'small area estimation'  
for ONE  way - see David Martin's grid-based approach
  • asked a question related to Population Projection
Question
1 answer
I've been using Zippin's method of calculating estimate of population size (calculating R based on k trappings and using the graph to find 1-q^k) I just was wondering how you can calculate 1-q^k without using the included graphs in his article. There must be a way of calculating it if he created the graph. I'm asking because I want to create a formula in Excel to calculate it automatically using R; but I don't know how.
Relevant answer
Answer
Take a look at this paper:  http://www.ncbi.nlm.nih.gov/pubmed/1784963
  • asked a question related to Population Projection
Question
3 answers
I am comparing longevity using as a proxy simulations of maximum conditional lifespan based on published matrix models. Most of the transitions that I’m using are based on annual population changes (from 1 year to the next year), however, some other transition matrices are based on variable time intervals (months, 2-year, 5-year, etc… How should I standardize these values to make them comparable? An easy way I have in mind would be just to divide the estimated lifespan by 12 in the case of monthly matrices or multiply by 2 when dealing with lifespan calculated based on biannual matrices, but I am not sure if that would be appropriated. Any suggestion?
Relevant answer
Answer
I think that in the supplementary information of Jones et al. 2014 Nature, you may find the response. They have also R code for calculations of life expectancy. 
Good luck!
  • asked a question related to Population Projection
Question
15 answers
Indeed, I would like to conduct a study on the analysis of the reliability of ape populations (Bonobo) and the probability of extinction over a defined time interval. This study is in order to improve protection strategies for this iconic and endangered species in the Democratic Republic of Congo. This is a demographic study with statistics, but a good read enable me to clearly define my question. Thank you for your recommendations
Relevant answer
Answer
Morris and Doak 2002 "Quantitative Conservation Biology" is a good intro to pop. viability analysis, goes through non-demographic and deterministic models through demographic and environmental stochastic PVA's, and comes with Matlab scripts you can get started with.
  • asked a question related to Population Projection
Question
7 answers
We have reliable methods based on camera trapping for carnivores which can be identified by individual markings. For social carnivores even this has limitation becoz of probability of no. of individuals in a photograph is not same as the actual no of individuals. Is there any other way?
Relevant answer
Answer
I am skeptical of the particle movement approach myself, and have had the opportunity to review manuscripts where estimates of abundance using this approach were very different than those simultaneously obtained using capture-recapture or mark resight approaches, which are more reliable.  One paper calculated estimates that differed by an order of magnitude, and I'm just not so sure that enough comparisons between this technique and more reliable approaches have occurred.  I would advocate use of an occupancy-based approach, where abundance (or density, if a buffer width with a biological basis can be confidently identified) is derived from differential presence/ absence (occupancy) and detection frequency parameters. In this scenario, the number of animals in each photo are best identified across a series of photos during a single trigger event.  However, even if not all can be accounted for, this number can be reasonably estimated assuming sufficient samples (i.e., photo events).  Hope this helps.