What are some problems of population forecasting/prediction methods?

Question

Hi.
Please list any many as you can think off the top of your head..
Thanks!

Answer 1

Any forecasting method relies heavily on historic data. There is a basic assumption made that the future data can be predicted on the basis of the past by following the trends.
Essentially it assumes that each data item oscillates about some mean value, i.e. if it goes above the mean significantly, it will go below te mean equally to compensate. Howver, if there is a paradigm shift in the value of the mean, then this assumption fails.
Also, since it is only possible to study a few parameters at a time, many other parameters that can affect the prediction model are kept constant, which can dignificantly affect the output.

Finally in highly complex systems uch as population, weather the system is CHAOTIC.

a chaotic system is not a random system. A chaotic system sometimes SEEMS random if you do not recognize that it is chaotic. For example, a roulette wheel is a chaotic system (trust me, it's not random, I'll explain why later). If you look at a fairly normal system such as a ball bouncing straight up and down against the ground, and you want to find out how high this ball will be after a certain amount of time, you would want to find out at what height the ball is dropped from, the strength of gravity, etc. and then you could easily plug these numbers into equations and then get the right answer. This is what happens in theory. In practice, since you will have to actually make measurements, what might happen is that your measurement might be a millimeter too high. If you did this, what would happen to the value that you would calculate with the slightly incorrect value? You would get an answer that was extremely close to what the ball actually did. A slight error in measurement is barely even noticeable.

Now lets consider a chaotic system, such as a ball on a roulette wheel. You might say, "hold on now, isn't a roulette table random?!", but it really isn't. Doesn't a bouncing roulette ball obey the same laws of physics as the ball bouncing against the ground? Because its behaviour is governed by laws that dictate exactly where the ball will land, the roulette wheel is not random. Another way to say that this system is not random, is to say that it is deterministic. If you wanted to find out where on the roulette table a ball would land you would need to find how high the ball was dropped from, how fast the table is spinning and the dimensions of the roulette table. Then, in theory you should be able to plug these numbers into equations and get the right answer. Again, in theory, you should be able to predict how the ball bounces straight up and down against the ground as easily as you can predict how a roulette ball will bounce on a roulette wheel. Of course if you actually tried to predict where the roulette ball would land, you'd get the wrong answer (otherwise gambling would much too easy).

Why are the two different? Like I said, in theory, you should get the exact answer if you plug the numbers into equations and you measured everything exactly right. However in practice, if you make a small mistake, with the bouncing ball you'd find that the answer you got from the equations would be off by only a little. With the roulette ball, however, that small inaccuracy will mean that the ball will take a COMPLETELY different path from the one you predicted and could land on the other side of the table.

If you can understand this point, then you understand the basic concept of chaos.

When a system like a roulette wheel can be thrown dramatically off-course with a very small change, we say that it is "sensitively dependant on initial conditions".

Answer 2

i've got additionally heard of many Jewish households having many little ones and one lady in u.s. the day earlier right this moment had her 18 newborn , (will seek for that hyperlink for you) do you be conscious of the different territory or u . s . a . that has purely one million.5 million human beings? No the smallest inhabitants i've got ever heard of is approximately 5 million in Denmark or Norway. inhabitants isn't the difficulty in Gaza, the difficulty is, is they have so little area there and are saved in penitentiary, consequently no longer loose to return and forth , say in step with risk to the West economic organization or different international places in the event that they could desire to choose for to realize this. Cheers!

Answer 3

Problems are that prediction is based on statistics. statistics may go wrong because of war, higher living standards, natural disasters etc.