how to calculate pop growth for 30 yr period.

[msherman]

Dear list

I have pop of 7,900,000 individuals who are 65 or older in year 2000. The rate of over the next 30 years is posited at .05 per year. I want to know what the pop size will be in the year 2030.
I can write syntax but there must be a shorter way.
compute year2001=year2000 + year2000*.05.
compute year2002=year2001 + year2001*.05.
...
...
compute year2030=year2029 + year2029*.05.

Suggestions appreciated.  martin sherman


compute year2003=year2002 + year2002*05.

Martin F. Sherman, Ph.D.
Professor of Psychology
Director of Masters Education: Thesis Track
Loyola College
Psychology Department
222 B Beatty Hall
4501 North Charles Street
Baltimore, MD 21210

410 617-2417 (office)
410 617-5341 (fax)

[hidden email]

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[Hector Maletta]

If it is supposed to grow by a proportion of 0.05 or 5% per year, the
formula for the population in 2030 would be:
COMPUTE YEAR2030=YEAR2000*((1.05)**30).
However, projecting a constant growth rate for such an age group during a 30
year period would be wrong, in my humble opinion. The rate would be
increased first by the gradual entrance of birth boomers into the elderly
group, and then dampened as they die out, and also affected by expected
increases in life expectancy. You better look at serious population
projections by age and sex produced by the US Census Bureau or the United
Nations.
Hector

-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of
Martin Sherman
Sent: 21 April 2008 16:04
To: [hidden email]
Subject: how to calculate pop growth for 30 yr period.

Dear list

I have pop of 7,900,000 individuals who are 65 or older in year 2000. The
rate of over the next 30 years is posited at .05 per year. I want to know
what the pop size will be in the year 2030.
I can write syntax but there must be a shorter way.
compute year2001=year2000 + year2000*.05.
compute year2002=year2001 + year2001*.05.
...
...
compute year2030=year2029 + year2029*.05.

Suggestions appreciated.  martin sherman


compute year2003=year2002 + year2002*05.

Martin F. Sherman, Ph.D.
Professor of Psychology
Director of Masters Education: Thesis Track
Loyola College
Psychology Department
222 B Beatty Hall
4501 North Charles Street
Baltimore, MD 21210

410 617-2417 (office)
410 617-5341 (fax)

[hidden email]

=====================
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[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD

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[Ian Martin-2]

N(t) = N(0)*e^rt

N(30)=354,053,436  (where r=1.05 and t=30)

Scarey, eh? But probably not realistic to expect 30 years of
exponential growth.

regards,
Ian.

Ian D. Martin, Ph.D.
Aquatic Ecologist


On 21 Apr, 2008, at 3:04 PM, Martin Sherman wrote:

> Dear list
>
> I have pop of 7,900,000 individuals who are 65 or older in year
> 2000. The rate of over the next 30 years is posited at .05 per
> year. I want to know what the pop size will be in the year 2030.
> I can write syntax but there must be a shorter way.
> compute year2001=year2000 + year2000*.05.
> compute year2002=year2001 + year2001*.05.
> ...
> ...
> compute year2030=year2029 + year2029*.05.
>
> Suggestions appreciated.  martin sherman
>
>
> compute year2003=year2002 + year2002*05.
>
> Martin F. Sherman, Ph.D.
> Professor of Psychology
> Director of Masters Education: Thesis Track
> Loyola College
> Psychology Department
> 222 B Beatty Hall
> 4501 North Charles Street
> Baltimore, MD 21210
>
> 410 617-2417 (office)
> 410 617-5341 (fax)
>
> [hidden email]
>
> =====================
> To manage your subscription to SPSSX-L, send a message to
> [hidden email] (not to SPSSX-L), with no body text
> except the
> command. To leave the list, send the command
> SIGNOFF SPSSX-L
> For a list of commands to manage subscriptions, send the command
> INFO REFCARD

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD