X-Message-Number: 26793
From: "Brent Fox" <>
Subject: Re: Predicted Cryonics Institute patients to 2044
Date: Wed, 10 Aug 2005 08:15:32 -0400

Re: Predicted Cryonics Institute patients to 2044

In CryoNet Message #26782 David Stodolsky wrote:

>The earlier years were eliminated,  
>because the slope of the line on a log plot was clearly different  
>from that starting in 1990. However, it doesn't appear that including  
>that data would make much difference (note that the Predicted for  
>earlier years is reasonable).

The more historical data that is incorporated would provide a more accurate
forecast.

>The patients received from ACS are excluded, since we don't know  
>their year of suspension and the growth curve for ACS may have been  
>different, in any case. 

The inclusion of ACS patients should be no different than a last minute
signup/suspension. ACS is a separate organization and the suspension dates
would be irrelevant in regards as to when CI accepted the patients.

>I looked at few other models. The cubic  
>function appeared to be better than a quadratic. However, the  
>straight line on the log plot indicated an exponential relationship  
>is most likely.

In running just the limited historical data  from 1990 (being fair to David,
excluding the ACS patients acquired in 2004), and projecting to 2050 yields
a more realistic view, and supports a Quadratic Trend growth model. The
Exponential Growth Model promoted fails accuracy measures (MAPE, MAD, MSD)
compared with the Quadratic Trend model.

Exponential Trend
MAPE = 12.6888
MAD = 2.7658
MSD = 12.4225

Quadratic Trend
MAPE  4.95273
MAD   0.85361
MSD   1.10717

Results of Quadratic Trend model using limited data (1990 - 2004 w/exclusion
of ACS patients - for comparison purposes in data used by David Stodolsky)
from 2005 <period 16> to 2050.

Period  Forecast
16        61.914
17        67.750
18        73.848
19        80.209
20        86.833
21        93.719
22       100.868
23       108.279
24       115.953
25       123.889
26       132.089
27       140.550
28       149.275
29       158.262
30       167.511
31       177.024
32       186.798
33       196.836
34       207.136
35       217.698
36       228.524
37       239.611
38       250.962
39       262.575
40       274.450
41       286.589
42       298.989
43       311.653
44       324.579
45       337.768
46       351.219
47       364.933
48       378.909
49       393.148
50       407.650
51       422.414
52       437.441
53       452.731
54       468.283
55       484.097
56       500.175
57       516.515
58       533.117
59       549.982
60       567.110
61       584.500


>While this data may be useful in sizing organizational capacity,  
>additional data, of a longitudinal type, is needed if models are to  
>be helpful in marketing. Thus, it would be desirable to know, for  
>each patient; when did they first contact the organization, when did  
>they become a member, when did they request sign up papers, and when  
>did they complete all arrangements, etc. Some demographic background  
>(age, sex, income, etc.) could also be useful in targeting a  
>marketing effort.

I agree with this.  It would also be beneficial if CI would release
Suspension Member figures by year since CI's inception.  This would enable
an accurate model of Suspension Membership to be determined, as opposed to a
generalized membership (organizational combined with suspension membership)
growth model.


Best regards to all,


Brent Fox

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