COVID-19 Analysis for April 3, 2020

1. Caveats and Comments
1. These are not confidential. You can freely share this output freely. The code is available at
https://github.com/StevenLShafer/COVID19/.
2. This is my analysis, not Stanford's analysis. My understanding is that Stanford's internal analysis, done to plan resource
allocation at Stanford, shows substantially longer doubling times. This is reassuring for those of us working at Stanford.
3. The data are from usafacts.org. Here is the file: https://usafactsstatic.blob.core.windows.net/public/data/covid-
19/covid_confirmed_usafacts.csv. The data are collected from state and county public health departments.
4. The model for the recent data is an asymptotic rise to peak: exp(intercept + peak * (1-exp(-k * delta time))).
5. The number printed on the graph is the projection for a week from today. Because that is only a week out, it is probably not far
off.
6. The "peak" in the caption is the estimated total peak at time = infinity from the model. I have very little confidence because it is a
projection well into the future, and very sensitive to small errors in that data.
7. The idiosyncratic locations chosen for the analysis reflect where Pamela and I have friends and family. I'm happy to add other
regions. Also, I'm happy to add people to the blind CC distribution list. Just let me know.
8. I'm not sure why Georgia is missing from the USA maps at the end. Likely a problem with the R library being used. I'm looking
into it.
9. Send any questions to steven.shafer@stanford.edu.
1

2. USA
523,124
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's USA Projection as of 2020-04-02
Initial doubling: 2.1 days, Predicted peak: 3,989,704
2

3. New York City
10,245
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's New York City Projection as of 2020-04-02
Initial doubling: 1.7 days, Predicted peak: 14,786
3

4. Santa Clara and San Mateo
2,119
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's Santa Clara and San Mateo Projection as of 2020-04-02
Initial doubling: 3.4 days, Predicted peak: 6,947
4

5. San Francisco
626
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's San Francisco Projection as of 2020-04-02
Initial doubling: 4.1 days, Predicted peak: 988
5

6. San Luis Obispo County
95
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Steve's San Luis Obispo County Projection as of 2020-04-02
Initial doubling: 2.2 days, Predicted peak: 98
6

7. King County (Seattle)
3,748
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's King County (Seattle) Projection as of 2020-04-02
Initial doubling: 2.2 days, Predicted peak: 9,599
7

8. Multnomah County (Portland)
231
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's Multnomah County (Portland) Projection as of 2020-04-02
Initial doubling: 1.7 days, Predicted peak: 335
8

9. Westchester County
20,906
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's Westchester County Projection as of 2020-04-02
Initial doubling: 2.0 days, Predicted peak: 86,981
9

10. Alameda County
480
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's Alameda County Projection as of 2020-04-02
Initial doubling: 2.6 days, Predicted peak: 571
10

11. Orleans Parish
4,068
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's Orleans Parish Projection as of 2020-04-02
Initial doubling: 2.4 days, Predicted peak: 19,991
11

12. Bergen County
8,850
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's Bergen County Projection as of 2020-04-02
Initial doubling: 1.8 days, Predicted peak: 80,956
12

13. Bay Area
3,259
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's Bay Area Projection as of 2020-04-02
Initial doubling: 2.6 days, Predicted peak: 10,956
13

14. California
20,529
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's California Projection as of 2020-04-02
Initial doubling: 3.0 days, Predicted peak: 122,664
14

15. Utah
1,890
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Date
Actual
(points)
/
Predicted
(line)
Phase
Pre log linear
Log linear
Current
Deaths
Steve's Utah Projection as of 2020-04-02
Initial doubling: 1.7 days, Predicted peak: 4,650
15

16. Doubling Time
Overall US: 4.6 days
0
2
4
6
State
Doubling
Time
Steve's 7 day estimation of doubling time 2020-04-02
16

17. Doubling Time
4.0
5.0
6.0
Doubling Time
Steve's 7 day estimation of doubling time 2020-04-02
17

18. All states in 1 week
Overall US: 20.4 cases
0
30
60
90
State
Cases
per
10,000
in
1
week
Steve's projection for 2020-04-08
18

19. Projected Cases per 10,000
25
50
75
100
Cases Per 10000
Steve's projection for 2020-04-08
19