COVID-19 short-term forecasts Confirmed 2020-03-20


Disclaimer

  • Forecasts produced by Jennie Castle, Jurgen Doornik, and David Hendry, researchers at the University of Oxford. These are our forecasts, and should not be considered official forecasts from, or endorsed by, any of: University of Oxford, Oxford Martin School, Nuffield College, Magdalen College, or any other University of Oxford institute.
  • These forecasts are short term time-series extrapolations of the data. They are not based on epidemiological modelling or simulations. The documentation that is provided is still in progress and not peer reviewed. All forecasts are uncertain: their success can only be determined afterwards. Many mitigation strategies are in place, which, if successful, invalidate our forecasts. An explanation of our methods is provided below.

Further information

  • We believe these forecasts fill a useful gap in the short run. They give an indication of what is likely to happen in the next few days, removing some aspect of surprise. Moreover, a noticeable drop in comparison to the extrapolations could be an indication that the implemented policies are having some impact. It is difficult to understand exponential growth. We hope that these forecasts may help to convince viewers to adhere to the policies implemented by their respective governments, and keep all arguments factual and measured.
  • We use the data repository for the 2019 Novel Coronavirus Visual Dashboard operated by the Johns Hopkins University Center for Systems Science and Engineering. This is updated daily, but it seems that our forecasts need slightly less frequent updating.
    US state data as of 2020-03-28 is courtesy of the New York Times. This seems to be a day behind the Johns Hopkins data.
  • We can only provide forecasts of what is measured. If confirmed cases are an underestimate of actual cases, then our forecasts will also be underestimates. Again: no other epidemiological data is used.
  • We will probably revise or update the methodology as we learn what is happening in the next few days or weeks.
  • Once the number of cases levels off, there is no need to provide these forecasts anymore.
  • Countries where the counts are very low or stable have been omitted.
  • We will probably revise or update the methodology as we learn what is happening in the next few days or weeks.
  • Once the number of cases levels off, there is no need to provide these forecasts anymore.
  • Countries where the counts are very low or stable have been omitted.
  • The graphs have dates on the horizontal axis (yyyy-mm-dd) and cumulative counts on the vertical axis. They show
    1. bold dark grey line (with circles): observed counts (Johns Hopkins CSSE);
    2. many light grey lines (with open circles): forecasts using different model settings and starting up to four periods back;
    3. red line (with open circles): single forecasts path using default model settings;
    4. black line (with crosses): average of all forecasts, recentered on the last observation;
    5. thin green lines: some indication of uncertainty around the red forecasts, but we do not know how reliable that is.
    Both the red line forecasts and the black lines are also given in the tables above. These forecasts differ, we are currently inclined to use the average forecasts.
  • The forecasts are constructed as follows:
    1. An overall `trend' is extracted by taking a window of the data at a time. In each window we draw `straight lines' which are selected using an automatic econometric procedure (`machine learning'). All straight lines are collected and averaged, giving the trend.
    2. Forecasts are made using the estimated trend, but we note that this must be done carefully, because simply extrapolating the flexible insample trend would lead to wildly fluctuating forecast. We use the `Cardt' method, which has been found to work well in other settings.
    3. Residuals from the trend are also forecasted, and combined with trend forecasts into an overall forecast.
  • EU-BS is Estonia, Latvia, and Lithuania together.
  • This paper describes the methodology and gives further references, but is still preliminary.

Confirmed count forecast average (bold black line in graphs) 2020-03-21 to 2020-03-25

DateUKEUATBEBSCZDEDKESFIFRGRIEITNLPLPTROSESINOCH
2020-03-20 3983 116514 2388 2257 816 833 19848 1255 20410 450 12612 495 683 47021 2994 425 1020 308 1639 341 1914 5294
2020-03-21 4800 138000 2810 2680 1030 1010 24500 1340 23600 510 14900 570 880 53800 3540 510 1300 350 1790 380 2050 6300
2020-03-22 5650 164000 3300 3120 1290 1190 29500 1400 27400 600 17600 660 1060 61500 4100 590 1580 400 1970 430 2180 7300
2020-03-23 6650 195000 3880 3640 1620 1390 35500 1460 31800 720 20800 770 1290 70200 4760 690 1930 460 2170 490 2330 8500
2020-03-24 7850 231000 4560 4260 2060 1640 42900 1530 36900 860 24500 910 1570 80200 5530 810 2350 530 2400 560 2490 9800
2020-03-25 9290 274000 5360 4980 2640 1930 51900 1600 43000 1030 28900 1060 1940 91600 6420 940 2890 600 2660 640 2660 11400

Confirmed count forecast average (bold black line in graphs) 2020-03-21 to 2020-03-25

DateAustraliaBrazilCanadaIranMalaysiaUS
2020-03-20 791 793 943 19644 1030 19100
2020-03-21 930 1000 1150 21200 1180 24400
2020-03-22 1070 1190 1380 23200 1370 29300
2020-03-23 1230 1440 1660 25300 1580 35500
2020-03-24 1420 1740 1990 27700 1840 43300
2020-03-25 1630 2110 2400 30300 2140 53100

Confirmed count forecast (bold red line in graphs) 2020-03-21 to 2020-03-25

DateUKEUATBEBSCZDEDKESFIFRGRIEITNLPLPTROSESINOCH
2020-03-20 3983 116514 2388 2257 816 833 19848 1255 20410 450 12612 495 683 47021 2994 425 1020 308 1639 341 1914 5294
2020-03-21 4530 135000 2620 2610 990 970 24100 1300 21400 450 14300 670 920 54200 3540 500 1320 330 1600 420 1930 6000
2020-03-22 5400 156000 2940 3030 1200 1120 29400 1360 23100 460 16200 830 1180 62100 4140 570 1650 360 1660 510 2000 6900
2020-03-23 6410 181000 3290 3500 1460 1310 35800 1430 25100 480 18400 1020 1540 71000 4820 660 2090 390 1730 610 2100 8100
2020-03-24 7590 209000 3670 4030 1760 1520 43400 1510 27200 500 20800 1240 1970 81100 5600 750 2600 430 1810 720 2210 9400
2020-03-25 8990 241000 4100 4640 2120 1760 52500 1590 29600 520 23500 1510 2520 92700 6500 860 3230 460 1890 850 2320 11000

Confirmed count forecast (bold red line in graphs) 2020-03-21 to 2020-03-25

DateAustraliaBrazilCanadaIranMalaysiaUS
2020-03-20 791 793 943 19644 1030 19100
2020-03-21 930 950 1150 20800 1030 24100
2020-03-22 1060 1150 1370 22200 1090 30100
2020-03-23 1220 1410 1630 23700 1160 38300
2020-03-24 1390 1690 1920 25300 1230 48100
2020-03-25 1580 2040 2260 27100 1310 60300

Initial visual evaluation of forecasts of Confirmed