X-Message-Number: 32349
Date: Sun, 31 Jan 2010 10:22:08 -0500
From: 
Subject: Re: CI growth rate decreasing?

David Stodolsky wrote:

> Using the more conservative 17%/year estimated growth rate (the  
> 1998-2004 rate was 23%/year):
>
> 127 suspendees predicted by 2010.1.1
>   85 suspendees actual by 2010.1.1
> (Ten patients received from the American Cryonics Society in 2004  
> are not included. Thus 58 suspendees on 2005.1.1 and 85 suspendees  
> on 2010.1.1)
>
> 1044 total members predicted by 2010.1.1
>   833 total members actual by 2010.1.1
> (476 members on 20041.1)
>
> Growth in suspendees is only 67% of expected.
> Growth in members is only 80% of expected.

http://www.cryonet.org/cgi-bin/dsp.cgi?msg=32348

   David's selection of data misrepresents the bigger
picture of what has been happening. Using data for
Cryonics Institute (CI) growth since 1990 gives:

CI GROWTH STATISTICS (since 1990)

______New_______New
___Patients___Members

1990____0_______07
1991____3_______08
1992____6_______08
1993____0_______07
1994____3_______10
1995____2_______13
1996____5_______05
1997____2_______05
1998____6_______19
1999____2_______41
2000____5_______42
2001____4_______62
2002____5_______63
2003____5_______76
2004____8+10____63
2005____3______100
2006____5_______76
2007____9_______71
2008____6_______61
2009____4_______62

   CI Membership growth was linear
in the single digits from 1990 to
1997, with a small spurt around the
time many disgruntled Alcor Members
left the organization (mostly to
join CryoCare). There was a growth
spurt in the 1997-2001 period which
is probably entirely attributable
to the fact that CI gained a website
and people started finding our
organization through the internet.
Membership growth has been roughly
constant since 2001, with a spurt
in 2005, which I have attributed
to a New York Times article (we
had a huge spurt of growth in the
weeks of the time of that article.

Selecting average growth from the
1998-2004 period as a predictive base
is arbitrary, as compared to
2001-2007 or 1990-1996.

  Nonetheless, after 2007 I was thinking
that patient growth was increasing
exponentially on the basis on 3 in
2005, 5 in 2006 and 9 in 2007. But
with 6 in 2008 and 4 in 2009 patient
growth looks to be dramatically declining.
Needless to say, these amounts of data
are not sufficient for statistically
significant prognostication (if there
is such a thing).

   A similar statement could be made
about Alcor growth as David has made
about CI growth by careful selection
of dates and periods. Selecting the
1985 to 1992 period of Alcor growth
as a baseline for prediction would
result in a huge expected exponential
membership growth. But Alcor growth
was hurt in the mid-1990s by the
formation of CryoCare. And since
1998 Alcor Membership growth has
been roughly linear (constant number
of new Members each year):

http://www.alcor.org/AboutAlcor/membershipstats.html

-- as has been the case with CI since 2001.

    -- Ben Best

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