Mid-2011 Population Estimates to be released on Wednesday

[greenforest32]

I wonder how this table (http://en.wikipedia.org/wiki/2010_United_States_Census#State_rankings) will change in the 2020 Census.

Here is the projected 2020 Census Population, based on current trends (last year's growth/loss x 8.75, added to the Mid-2011 population):

SORTED BY 2020 POPULATION:



SORTED BY NUMERICAL GROWTH/LOSS:



SORTED BY PERCENTAGE GROWTH/LOSS:

Was just thinking of making that myself. Nice

[muon2]

I wonder how this table (http://en.wikipedia.org/wiki/2010_United_States_Census#State_rankings) will change in the 2020 Census.

Here is the projected 2020 Census Population, based on current trends (last year's growth/loss x 8.75, added to the Mid-2011 population):

SORTED BY 2020 POPULATION:



SORTED BY NUMERICAL GROWTH/LOSS:



SORTED BY PERCENTAGE GROWTH/LOSS:

Your formula isn't very accurate since it assumes that the numerical growth stays fixed over the decade, when the projection should be based on a constant rate of growth. If you want to assume constant numerical growth the factor of 8.75 is not correct. Since the original period is 1.25 years the the remaining period is 8.75 but that is a factor of 8.75/1.25 = 7 times the amount of growth. By using 8.75 instead of 7 you overestimate the final population.

In reality a constant rate of growth compounds with each year. For example assume that a population of 1000 has an annual growth rate of 1% or 10. A constant numerical growth gives a population of 1100 at the end, while a constant rate of growth gives 1105 after 10 years. The effect is greater as the rate increases, so your method will have the fast growing states grow less compared to the slow growing states.

To get the correct projections including the effects of compounding you need to use the financial functions in the spreadsheet to get the rate and then the new future value. The functions and format depend on the spreadsheet syntax. The result can also be obtained directly from the math, using rate = (current/census)^(1/period)-1 where period = 1.25, and projection = census*(1+rate)^(decade) where decade = 10.

[Tender Branson]

I wonder how this table (http://en.wikipedia.org/wiki/2010_United_States_Census#State_rankings) will change in the 2020 Census.

Here is the projected 2020 Census Population, based on current trends (last year's growth/loss x 8.75, added to the Mid-2011 population):

(charts)

Your formula isn't very accurate since it assumes that the numerical growth stays fixed over the decade, when the projection should be based on a constant rate of growth. If you want to assume constant numerical growth the factor of 8.75 is not correct. Since the original period is 1.25 years the the remaining period is 8.75 but that is a factor of 8.75/1.25 = 7 times the amount of growth. By using 8.75 instead of 7 you overestimate the final population.

In reality a constant rate of growth compounds with each year. For example assume that a population of 1000 has an annual growth rate of 1% or 10. A constant numerical growth gives a population of 1100 at the end, while a constant rate of growth gives 1105 after 10 years. The effect is greater as the rate increases, so your method will have the fast growing states grow less compared to the slow growing states.

To get the correct projections including the effects of compounding you need to use the financial functions in the spreadsheet to get the rate and then the new future value. The functions and format depend on the spreadsheet syntax. The result can also be obtained directly from the math, using rate = (current/census)^(1/period)-1 where period = 1.25, and projection = census*(1+rate)^(decade) where decade = 10.

I know very well what you want to say, but after only 1.25 years since the Census, I found it more convinient to just multiply the past year's growth by 8.75 to get the 2020 Census numbers. There are just too many variables that make it impossible to predict the population 8 years from now. Like I said above, the economy could grow at a faster pace in the next years, which could lead to higher immigration balances again from other parts of the world and/or the natural increase could be higher by 300K people by the end of the decade. I could create 10 different models right now, one based on numerical projections, one based on percentage growth etc. etc. It will only be in the years 2017/18/19 when these projections would get somewhat more accurate ...

[muon2]

I wonder how this table (http://en.wikipedia.org/wiki/2010_United_States_Census#State_rankings) will change in the 2020 Census.

Here is the projected 2020 Census Population, based on current trends (last year's growth/loss x 8.75, added to the Mid-2011 population):

(charts)

Your formula isn't very accurate since it assumes that the numerical growth stays fixed over the decade, when the projection should be based on a constant rate of growth. If you want to assume constant numerical growth the factor of 8.75 is not correct. Since the original period is 1.25 years the the remaining period is 8.75 but that is a factor of 8.75/1.25 = 7 times the amount of growth. By using 8.75 instead of 7 you overestimate the final population.

In reality a constant rate of growth compounds with each year. For example assume that a population of 1000 has an annual growth rate of 1% or 10. A constant numerical growth gives a population of 1100 at the end, while a constant rate of growth gives 1105 after 10 years. The effect is greater as the rate increases, so your method will have the fast growing states grow less compared to the slow growing states.

To get the correct projections including the effects of compounding you need to use the financial functions in the spreadsheet to get the rate and then the new future value. The functions and format depend on the spreadsheet syntax. The result can also be obtained directly from the math, using rate = (current/census)^(1/period)-1 where period = 1.25, and projection = census*(1+rate)^(decade) where decade = 10.

I know very well what you want to say, but after only 1.25 years since the Census, I found it more convinient to just multiply the past year's growth by 8.75 to get the 2020 Census numbers. There are just too many variables that make it impossible to predict the population 8 years from now. Like I said above, the economy could grow at a faster pace in the next years, which could lead to higher immigration balances again from other parts of the world and/or the natural increase could be higher by 300K people by the end of the decade. I could create 10 different models right now, one based on numerical projections, one based on percentage growth etc. etc. It will only be in the years 2017/18/19 when these projections would get somewhat more accurate ...

But why 8.75? Is it based on any approximation, or just a guess? If a guess what motivates it?

Even if I take your approximation on your spreadsheet I can't duplicate the results. For example the Census report had IL grow by 38625 last year. If I multiply that by 8.75 I get 337969. If I add that to the 2011 midyear estimate of 12869257, I get 13207226 which is quite a bit larger than the number you show. If I derate the growth by a factor of 1.25 and then multiply by 8.75 and add to the midyear total I get 13139632. That still doesn't match the value in your chart.

Can you tell me where I'm off?

[Tender Branson]

I wonder how this table (http://en.wikipedia.org/wiki/2010_United_States_Census#State_rankings) will change in the 2020 Census.

Here is the projected 2020 Census Population, based on current trends (last year's growth/loss x 8.75, added to the Mid-2011 population):

(charts)

Your formula isn't very accurate since it assumes that the numerical growth stays fixed over the decade, when the projection should be based on a constant rate of growth. If you want to assume constant numerical growth the factor of 8.75 is not correct. Since the original period is 1.25 years the the remaining period is 8.75 but that is a factor of 8.75/1.25 = 7 times the amount of growth. By using 8.75 instead of 7 you overestimate the final population.

In reality a constant rate of growth compounds with each year. For example assume that a population of 1000 has an annual growth rate of 1% or 10. A constant numerical growth gives a population of 1100 at the end, while a constant rate of growth gives 1105 after 10 years. The effect is greater as the rate increases, so your method will have the fast growing states grow less compared to the slow growing states.

To get the correct projections including the effects of compounding you need to use the financial functions in the spreadsheet to get the rate and then the new future value. The functions and format depend on the spreadsheet syntax. The result can also be obtained directly from the math, using rate = (current/census)^(1/period)-1 where period = 1.25, and projection = census*(1+rate)^(decade) where decade = 10.

I know very well what you want to say, but after only 1.25 years since the Census, I found it more convinient to just multiply the past year's growth by 8.75 to get the 2020 Census numbers. There are just too many variables that make it impossible to predict the population 8 years from now. Like I said above, the economy could grow at a faster pace in the next years, which could lead to higher immigration balances again from other parts of the world and/or the natural increase could be higher by 300K people by the end of the decade. I could create 10 different models right now, one based on numerical projections, one based on percentage growth etc. etc. It will only be in the years 2017/18/19 when these projections would get somewhat more accurate ...

But why 8.75? Is it based on any approximation, or just a guess? If a guess what motivates it?

Even if I take your approximation on your spreadsheet I can't duplicate the results. For example the Census report had IL grow by 38625 last year. If I multiply that by 8.75 I get 337969. If I add that to the 2011 midyear estimate of 12869257, I get 13207226 which is quite a bit larger than the number you show. If I derate the growth by a factor of 1.25 and then multiply by 8.75 and add to the midyear total I get 13139632. That still doesn't match the value in your chart.

Can you tell me where I'm off?

Yeah.

You are using the growth for April 1, 2010 until July 1, 2011.

I'm just using the July 1, 2010 to July 1, 2011 data:

http://www.census.gov/popest/data/maps/2011/MAP-EST2011-01.xls

In the case of Illinois for example, the growth was 27.277 during that year.

27.277 x 8.75 = 238.674 + 12.869.257 (Mid-2011) => 13.107.931

[krazen1211]

Would be very interesting to add a column to that sheet detailing the number of Congressional seats. Someone I know has an excel template that calculates it quickly.

[muon2]

Would be very interesting to add a column to that sheet detailing the number of Congressional seats. Someone I know has an excel template that calculates it quickly.

I posted that already.

I used the July 2011 estimates and the April 2010 Census base to get an annual growth rate. This correctly accounts for the 15 month period between the Census and the estimate. I then applied the annual growth rate to the 2010 reapportionment population to get the 2020 projection. This accounts for the extra overseas population used in reapportionment but not for redistricting. Ten years is a long stretch for a simple model like this, but here are the projected changes.

CA +1
CO +1
FL +1
IL -1
MI -1
MN -1
NY -1
NC +1
OH -1
PA -1
RI -1
TX +3
VA +1
WV -1

The bubble seats in this projection are based on the last five awarded and the next five in line.
The last five awarded are CO-8, AL-7, VA-12, CA-54, and FL-28 (#435).
The next five in line are WV-3, OR-6, NY-27, AZ-10, LA-7.

[muon2]

Thanks, I was using the Census spreadsheet from their first link, and you were using the second link.

I still think that with the power and ease of a spreadsheet one ought to at least estimate the compounding effects. It matters for estimating seats in 2020, since adds more to the fast growing states.

[Tender Branson]

2 other ways of projecting the 2020 population would be constant relative population growth rates of either the past year (Mid-2010 to Mid-2011) or the past 1.25 years, projected to 2020:

Scenario A: April 1, 2010 -> July 1, 2011 growth rate: 0.7368565%
Scenario B: July 1, 2010 -> July 1, 2011 growth rate: 0.7311597%

In scenario A, the April 1, 2020 population for the US would be 332.265.030
In scenario B, the April 1, 2020 population for the US would be 332.100.653

This has to do with the fact that the 1/4 year between April 1, 2010 to July 1, 2010 had slightly higher relative growth (0.7596469%) than the year that followed.

[Tender Branson]

I still think that with the power and ease of a spreadsheet one ought to at least estimate the compounding effects. It matters for estimating seats in 2020, since adds more to the fast growing states.

Correct.

For example Texas:

Numerical growth, the same for the next 8.75 years: 29.360.312
Relative growth, the same for the next 8.75 years: 29.673.284

A difference of 300.000 between the 2 models ...

[muon2]

2 other ways of projecting the 2020 population would be constant relative population growth rates of either the past year (Mid-2010 to Mid-2011) or the past 1.25 years, projected to 2020:

Scenario A: April 1, 2010 -> July 1, 2011 growth rate: 0.7368565%
Scenario B: July 1, 2010 -> July 1, 2011 growth rate: 0.7311597%

In scenario A, the April 1, 2020 population for the US would be 332.265.030
In scenario B, the April 1, 2020 population for the US would be 332.100.653

This has to do with the fact that the 1/4 year between April 1, 2010 to July 1, 2010 had slightly higher relative growth (0.7596469%) than the year that followed.

I prefer scenario A since it averages a longer period. If there are no seasonal effects in the estimate, it should provide a slightly better projection.

[Seattle]

Washington barely held it's title as 2nd biggest Western state in 2010. Hopefully we really will keep in 2020, too.

I would not be surprised if we did. With the new 737MAX secured for Renton, and a good 1/3 of Boeing's workforce (both engineers and machinests) retiring in the next 10 years, combined with (I presume) further growth of Microsoft and other software companies, Washington growth is probably going to be fairly decent.

[krazen1211]

Would be very interesting to add a column to that sheet detailing the number of Congressional seats. Someone I know has an excel template that calculates it quickly.

I posted that already.

I used the July 2011 estimates and the April 2010 Census base to get an annual growth rate. This correctly accounts for the 15 month period between the Census and the estimate. I then applied the annual growth rate to the 2010 reapportionment population to get the 2020 projection. This accounts for the extra overseas population used in reapportionment but not for redistricting. Ten years is a long stretch for a simple model like this, but here are the projected changes.

CA +1
CO + 1
FL +1
IL -1
MI -1
MN -1
NY -1
NC +1
OH -1
PA -1
RI -1
TX +3
VA +1
WV -1

The bubble seats in this projection are based on the last five awarded and the next five in line.
The last five awarded are CO-8, AL-7, VA-12, CA-54, and FL-28 (#435).
The next five in line are WV-3, OR-6, NY-27, AZ-10, LA-7.

Ah, thanks. Incidentally whomever wins the 2011 Texas legal battle will struggle in 2021 presuming a Republican trifecta again. The GOP might finally have to yield the Austin seat and will likely certainly yield the 2nd Metroplex seat. Or, if those seats are yielded now they'll be plopping down 3 new GOP seats in the suburbs of the 3 big metro areas.

The rest seem fairly Dem favored. IL might have to cut a Chicago seat, but PA and OH will likely have to cut Republicans unless Altmire holds that PA-12 for the decade.

[BigSkyBob]

I used the July 2011 estimates and the April 2010 Census base to get an annual growth rate. This correctly accounts for the 15 month period between the Census and the estimate. I then applied the annual growth rate to the 2010 reapportionment population to get the 2020 projection. This accounts for the extra overseas population used in reapportionment but not for redistricting. Ten years is a long stretch for a simple model like this, but here are the projected changes.

CA +1
CO +1
FL +1
IL -1
MI -1
MN -1
NY -1
NC +1
OH -1
PA -1
RI -1
TX +3
VA +1
WV -1

The bubble seats in this projection are based on the last five awarded and the next five in line.
The last five awarded are CO-8, AL-7, VA-12, CA-54, and FL-28 (#435).
The next five in line are WV-3, OR-6, NY-27, AZ-10, LA-7.

I doubt the methodology here. Census 2010 had horrible undercount problems in some areas. Comparing July 2010 estimates to July 2011 estimates I think is the more apt comparison.

Obama politicizes everything. My assumption was that he would run Census 2010 to net Democrats more seats. What really happened, was that he hired enumerators, trained them, and laid them off, only to rehire them, and retrain them. He did that to increase the number of "jobs" he created. The problem was those enumerators were really needed in areas such as Queens. The Census was a mess in NYC, and, the final count was below estimates derived by statistical counting models.

If the Republicans hold the New York Senate this election, one of the reasons will be Obama's incompetence in adminsistering the Census.

[muon2]

I used the July 2011 estimates and the April 2010 Census base to get an annual growth rate. This correctly accounts for the 15 month period between the Census and the estimate. I then applied the annual growth rate to the 2010 reapportionment population to get the 2020 projection. This accounts for the extra overseas population used in reapportionment but not for redistricting. Ten years is a long stretch for a simple model like this, but here are the projected changes.

CA +1
CO +1
FL +1
IL -1
MI -1
MN -1
NY -1
NC +1
OH -1
PA -1
RI -1
TX +3
VA +1
WV -1

The bubble seats in this projection are based on the last five awarded and the next five in line.
The last five awarded are CO-8, AL-7, VA-12, CA-54, and FL-28 (#435).
The next five in line are WV-3, OR-6, NY-27, AZ-10, LA-7.

I doubt the methodology here. Census 2010 had horrible undercount problems in some areas. Comparing July 2010 estimates to July 2011 estimates I think is the more apt comparison.

Obama politicizes everything. My assumption was that he would run Census 2010 to net Democrats more seats. What really happened, was that he hired enumerators, trained them, and laid them off, only to rehire them, and retrain them. He did that to increase the number of "jobs" he created. The problem was those enumerators were really needed in areas such as Queens. The Census was a mess in NYC, and, the final count was below estimates derived by statistical counting models.

If the Republicans hold the New York Senate this election, one of the reasons will be Obama's incompetence in adminsistering the Census.

July 1 estimates from the Census used here are based on the April 1, 2010 Census according to the Bureau. So if the April 2010 values are suspect so would any analysis based only on the July 2010 to July 2011 estimates. In any case, I want to model the Census methodology since that method, including any undercount, is the best way to project reapportionment counts.

[Skill and Chance]

Would be very interesting to add a column to that sheet detailing the number of Congressional seats. Someone I know has an excel template that calculates it quickly.

I posted that already.

I used the July 2011 estimates and the April 2010 Census base to get an annual growth rate. This correctly accounts for the 15 month period between the Census and the estimate. I then applied the annual growth rate to the 2010 reapportionment population to get the 2020 projection. This accounts for the extra overseas population used in reapportionment but not for redistricting. Ten years is a long stretch for a simple model like this, but here are the projected changes.

CA +1
CO + 1
FL +1
IL -1
MI -1
MN -1
NY -1
NC +1
OH -1
PA -1
RI -1
TX +3
VA +1
WV -1

The bubble seats in this projection are based on the last five awarded and the next five in line.
The last five awarded are CO-8, AL-7, VA-12, CA-54, and FL-28 (#435).
The next five in line are WV-3, OR-6, NY-27, AZ-10, LA-7.

Ah, thanks. Incidentally whomever wins the 2011 Texas legal battle will struggle in 2021 presuming a Republican trifecta again. The GOP might finally have to yield the Austin seat and will likely certainly yield the 2nd Metroplex seat. Or, if those seats are yielded now they'll be plopping down 3 new GOP seats in the suburbs of the 3 big metro areas.

The rest seem fairly Dem favored. IL might have to cut a Chicago seat, but PA and OH will likely have to cut Republicans unless Altmire holds that PA-12 for the decade.

I would base it on what a court or commission would do in each state, since we don't know who will be in control.  Almost all of the gains would probably be Democratic seats, but so are almost all of the losses.  It does look like a significantly better picture for Democrats in the electoral college than the past several decades if CO and VA hold for them.  Also, remember that mobility is restricted during bad economic times, so if there is a boom later in the decade, I would expect that FL-29, AZ-10, NV-07, TX-40, etc. will be happening in 2020.

[Yelnoc]

I expect by 2020, most of the nation's population will be concentrated in the sunbelt region (perhaps + Virginia).  The below states might be enough for a candidate to carry the election in 2020.

[krazen1211]

I would base it on what a court or commission would do in each state, since we don't know who will be in control.  Almost all of the gains would probably be Democratic seats, but so are almost all of the losses.  It does look like a significantly better picture for Democrats in the electoral college than the past several decades if CO and VA hold for them.  Also, remember that mobility is restricted during bad economic times, so if there is a boom later in the decade, I would expect that FL-29, AZ-10, NV-07, TX-40, etc. will be happening in 2020.

Well, based on that I come up with:

CA +1 D
CO + 1 D
FL +1 R
IL -1 D
MI -1 D
MN -1 R
NY -1 D
NC +1 D
OH -1 R
PA -1 R
RI -1 D
TX +2D +1R (based on the legislative map)
VA +1 D
WV -1 R

[jimrtex]

Thanks, I was using the Census spreadsheet from their first link, and you were using the second link.

I still think that with the power and ease of a spreadsheet one ought to at least estimate the compounding effects. It matters for estimating seats in 2020, since adds more to the fast growing states.

A presumption of compounding might not be valid.

Even if fertility and mortality rates are constant, birth and death rates might not be, due to age distribution effects.  Interstate migration to a state is dependent on migration from other states.  As the population of Arizona, Nevada, and Idaho grow due to people moving from California, their growth rate may decline as the relative ratio of populations decreases.

There may also be seasonal factors in population growth.  People with children may be more likely to move during the summer.  The one year growth rate from July 1, 2010 to July 1, 2011 may be more reflective of trends than the 5-quarter growth rate that includes two 2nd quarters.