This document provides caveats and comments about COVID-19 projections for various locations in the US and globally. It notes that the analysis reflects the author's understanding and Stanford may have different internal projections. Data sources and modeling approaches are also outlined. Questions about the analysis can be directed to the author.

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 added global data, taken from https://github.com/CSSEGISandData/COVID-19. This is the Johns Hopkins data repository.
Global graphs are at the end.
9. Send any questions to steven.shafer@stanford.edu.
1

2. USA
449,658
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 2020-04-03
Initial doubling: 2.1 days, Predicted peak: 1,093,953
0
10,000
20,000
30,000
Feb Mar Apr May Jun
Date
NewCases/Day
2

3. New York City
10,277
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 2020-04-03
Initial doubling: 1.7 days, Predicted peak: 13,765
0
200
400
600
Feb Mar Apr May Jun
Date
NewCases/Day
3

4. Santa Clara and San Mateo
2,276
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 2020-04-03
Initial doubling: 3.4 days, Predicted peak: 7,111
0
50
100
Feb Mar Apr May Jun
Date
NewCases/Day
4

5. San Francisco
587
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 2020-04-03
Initial doubling: 4.1 days, Predicted peak: 707
0
20
40
60
Feb Mar Apr May Jun
Date
NewCases/Day
5

6. San Luis Obispo County
100
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 2020-04-03
Initial doubling: 2.2 days, Predicted peak: 105
0.0
2.5
5.0
7.5
10.0
Feb Mar Apr May Jun
Date
NewCases/Day
6

7. King County (Seattle)
3,914
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 2020-04-03
Initial doubling: 2.2 days, Predicted peak: 9,563
0
50
100
150
Feb Mar Apr May Jun
Date
NewCases/Day
7

8. Multnomah County (Portland)
260
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 2020-04-03
Initial doubling: 1.7 days, Predicted peak: 388
0.0
5.0
10.0
15.0
Feb Mar Apr May Jun
Date
NewCases/Day
8

9. Westchester County
21,288
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 2020-04-03
Initial doubling: 2.0 days, Predicted peak: 78,362
0
500
1,000
1,500
Feb Mar Apr May Jun
Date
NewCases/Day
9

10. Alameda County
532
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 2020-04-03
Initial doubling: 2.6 days, Predicted peak: 666
0
10
20
30
Feb Mar Apr May Jun
Date
NewCases/Day
10

11. Orleans Parish
4,914
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 2020-04-03
Initial doubling: 2.4 days, Predicted peak: 24,520
0
100
200
300
400
Feb Mar Apr May Jun
Date
NewCases/Day
11

12. Bergen County
9,876
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 2020-04-03
Initial doubling: 1.8 days, Predicted peak: 81,219
0
500
1,000
1,500
Feb Mar Apr May Jun
Date
NewCases/Day
12

13. Bay Area
3,479
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 2020-04-03
Initial doubling: 2.6 days, Predicted peak: 11,058
0
50
100
150
200
Feb Mar Apr May Jun
Date
NewCases/Day
13

14. California
22,524
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 2020-04-03
Initial doubling: 3.0 days, Predicted peak: 123,883
0
500
1,000
1,500
2,000
Feb Mar Apr May Jun
Date
NewCases/Day
14

15. Utah
1,905
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 2020-04-03
Initial doubling: 1.7 days, Predicted peak: 3,921
0
30
60
90
120
Feb Mar Apr May Jun
Date
NewCases/Day
15

16. Doubling Time
Overall US: 4.9 days
0
2
4
6
8
State
DoublingTime
Steve's 7 day estimation of doubling time 2020-04-03
16

17. Doubling Time
4.0
5.0
6.0
7.0
Doubling Time
Steve's 7 day estimation of doubling time 2020-04-03
17

18. All states in 1 week
Overall US: 21.1 cases
0
25
50
75
100
State
Casesper10,000in1week
Steve's projection for 2020-04-09
18

19. Projected Cases per 10,000
25
50
75
100
Cases Per 10000
Steve's projection for 2020-04-09
19

20. Italy
149,866
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 Italy Projection as of 2020-04-03
Initial doubling: 2.4 days, Predicted peak: 217,322
0
2,000
4,000
Feb Mar Apr May Jun
Date
NewCases/Day
20

21. Spain
203,404
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 Spain Projection as of 2020-04-03
Initial doubling: 1.9 days, Predicted peak: 750,116
0
5,000
10,000
Feb Mar Apr May Jun
Date
NewCases/Day
21

22. France
97,814
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 France Projection as of 2020-04-03
Initial doubling: 2.3 days, Predicted peak: 317,810
0
2,000
4,000
6,000
Feb Mar Apr May Jun
Date
NewCases/Day
22

23. Portugal
16,205
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 Portugal Projection as of 2020-04-03
Initial doubling: 2.0 days, Predicted peak: 37,295
0
250
500
750
1,000
Feb Mar Apr May Jun
Date
NewCases/Day
23

24. Sweden
6,403
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 Sweden Projection as of 2020-04-03
Initial doubling: 1.9 days, Predicted peak: 13,745
0
50
100
150
200
250
Feb Mar Apr May Jun
Date
NewCases/Day
24

25. Netherlands
23,740
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 Netherlands Projection as of 2020-04-03
Initial doubling: 1.4 days, Predicted peak: 77,298
0
500
1,000
Feb Mar Apr May Jun
Date
NewCases/Day
25

26. United Kingdom
65,286
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 United Kingdom Projection as of 2020-04-03
Initial doubling: 2.7 days, Predicted peak: 344,057
0
2,000
4,000
6,000
Feb Mar Apr May Jun
Date
NewCases/Day
26