COVID-19 short-term forecasts Confirmed 2021-05-17 Latin American Countries


General information

  • 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, or Magdalen College.
  • These forecasts are short term time-series extrapolations of the data. They are not based on epidemiological modelling or simulations. 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.
  • A list of notes is below. The most recent note:
    [2021-04-29]The `legacy' download for areas of England is stuck at April 26, so we switched to the newer downloads. The results now include Scotland, Wales, and Northern Ireland. The map, however, only shows England.

Peak increase in estimated trend of Confirmed in Latin America 2021-05-17

ArgentinaBahamasBarbadosBelizeBoliviaBrazilChileColombiaCosta RicaDominican RepublicEcuadorEl SalvadorGuatemalaGuyanaHaitiHondurasJamaicaMexicoNicaraguaPanamaParaguayPeruSurinameTrinidad and TobagoUruguayVenezuela
Peak date (mm-dd) --2021-04-252021-02-1812-03 --2021-03-242021-04-092021-04-18 --2021-01-182021-04-232021-04-112021-04-16 --2021-01-232021-02-032021-03-182021-01-2005-262021-01-072021-04-172021-04-16 --2021-05-142021-04-092021-04-05
Peak daily increment 57 106 1122 74847 7144 17130 1589 1983 675 1398 63 1356 662 16981 177 3354 2636 9097 606 5275 1368
Days since peak 22 88 165 54 38 29 119 24 36 31 114 103 60 117 356 130 30 31 3 38 42
Last total 3335965 11225 3968 12742 334824 15657391 1292096 3131410 288626 277919 410870 71479 241528 15352 13460 227516 47396 2382745 7086 371145 315547 1889052 12107 16549 242906 216415
Last daily increment 28680 201 1 28 2257 30148 5548 12984 5885 731 741 0 159 81 67 797 77 822 0 268 2020 0 157 294 2394 1114
Last week 144868 317 18 38 14615 374686 35550 99684 14912 5110 8275 1099 5262 821 281 5398 575 14352 0 2777 13486 35682 801 2747 17059 6299
Previous peak date10-1610-17 -- --2021-01-2808-0406-062021-01-1609-1407-2604-2408-0507-1809-2106-0406-2809-2210-05 -- -- --08-0208-1309-19 --09-08
Previous peak daily increment 14331 104 2232 45270 7348 17013 1226 1405 7778 420 2590 77 177 795 160 22833 8380 94 119 1085
Low between peaks 7 19229 1343 3454 400 -4305 70 423 6 305 50 4599 1490 4 276

Confirmed count forecast Latin America (bold red line in graphs) 2021-05-18 to 2021-05-24

DateArgentinaBahamasBoliviaBrazilChileColombiaCosta RicaDominican RepublicEcuadorEl SalvadorGuatemalaGuyanaHaitiHondurasJamaicaMexicoPanamaParaguayPeruSurinameTrinidad and TobagoUruguayVenezuela
2021-05-17 3335965 11225 334824 15657391 1292096 3131410 288626 277919 410870 71479 241528 15352 13460 227516 47396 2382745 371145 315547 1889052 12107 16549 242906 216415
2021-05-18 3349000 11230 336500 15717000 1296000 3146000 289300 278400 413800 71620 242700 15500 13480 228400 47500 2386000 371100 317600 1895000 12230 16610 244900 217600
2021-05-19 3368000 11290 338000 15783000 1300000 3162000 291600 279100 416500 71720 244100 15690 13480 229300 47670 2390000 371300 320000 1905000 12320 17040 247000 218900
2021-05-20 3392000 11340 339500 15846000 1306000 3179000 294200 279800 418400 71840 245300 15850 13480 230200 47810 2394000 371500 322300 1907000 12420 17440 250300 220100
2021-05-21 3413000 11390 340800 15917000 1313000 3195000 296600 280600 420000 71960 246600 16000 13480 231000 47920 2397000 371700 324500 1918000 12520 17800 253000 221200
2021-05-22 3431000 11440 342100 15975000 1319000 3211000 296600 281100 422400 72070 247300 16140 13480 231900 48030 2400000 371900 326300 1922000 12620 18170 255400 222400
2021-05-23 3445000 11480 343400 16008000 1324000 3225000 296600 282000 423100 72190 247300 16270 13480 232800 48130 2401000 372100 327600 1930000 12720 18530 257400 223500
2021-05-24 3467000 11530 344600 16032000 1329000 3236000 302000 282600 424000 72310 247500 16400 13490 233600 48230 2402000 372400 329400 1930000 12820 18890 259400 224500

Confirmed count average forecast Latin America (bold black line in graphs) 2021-05-18 to 2021-05-24

DateArgentinaBahamasBoliviaBrazilChileColombiaCosta RicaDominican RepublicEcuadorEl SalvadorGuatemalaGuyanaHaitiHondurasJamaicaMexicoPanamaParaguayPeruSurinameTrinidad and TobagoUruguayVenezuela
2021-05-17 3335965 11225 334824 15657391 1292096 3131410 288626 277919 410870 71479 241528 15352 13460 227516 47396 2382745 371145 315547 1889052 12107 16549 242906 216415
2021-05-18 3361000 11280 336800 15729000 1296000 3146000 290600 278700 411700 71600 242300 15460 13500 228400 47460 2385000 371400 317600 1892000 12240 16920 245600 217500
2021-05-19 3382000 11330 338500 15798000 1300000 3161000 293000 279300 413100 71720 243400 15580 13500 229200 47550 2388000 371700 319800 1899000 12340 17350 247900 218400
2021-05-20 3404000 11370 340200 15864000 1305000 3176000 295300 280000 414200 71840 244200 15690 13510 230000 47650 2390000 371900 322000 1901000 12450 17740 250800 219200
2021-05-21 3426000 11410 341900 15939000 1312000 3191000 297500 280700 415200 71960 245200 15810 13520 230800 47740 2393000 372100 324000 1909000 12570 18100 253500 219900
2021-05-22 3446000 11450 343600 15998000 1317000 3206000 298500 281300 416600 72080 245900 15920 13530 231600 47830 2395000 372400 325800 1913000 12650 18500 255900 220700
2021-05-23 3462000 11480 344900 16032000 1323000 3220000 299500 282000 417400 72210 246300 16030 13550 232400 47910 2397000 372600 327300 1919000 12740 18890 257900 221400
2021-05-24 3481000 11540 346500 16054000 1328000 3234000 302700 282600 418300 72330 246600 16150 13560 233200 47990 2398000 372800 329100 1920000 12820 19270 259900 222100

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 we tend to update our forecasts only every other day.
    US state data as of 2020-03-28 is courtesy of the New York Times.
  • 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. No other epidemiological data is used. Data definition and collection differs between countries and may change over time.
  • We will 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 forecast, and combined with trend forecasts into an overall forecast.
  • Scenario forecasts are constructed very differently: smooth versions of the Chinese experience are matched at different lag lengths with the path of each country. This probably works best from the peak, or the slowdown just before (but we include it for the UK nonetheless).
  • The forecast evaluation shows past forecasts, together with the outcomes (in the grey line with circles).
  • EU-BS is Estonia, Latvia, and Lithuania together.
  • This paper describes the methodology and gives further references. Also available as Nuffield Economics Discussion Paper 2020-W06. Still preliminary is the documentation of the medium term forecasts.

Recent changes and notes

[2021-04-29]The `legacy' download for areas of England is stuck at April 26, so we switched to the newer downloads. The results now include Scotland, Wales, and Northern Ireland. The map, however, only shows England.
[2021-01-07]Slideshow of forecasts, errors, and actuals 2020-06-30 to 2021-01-02: how England lost the battle.
[2020-10-27]Statistical short-term forecasting of the COVID-19 Pandemic (Jurgen Doornik, Jennie Castle, and David Hendry) is now published at the Journal of Clinical Immunology and Immunotherapy. open access
[2020-10-11]Short-term forecasting of the coronavirus pandemic (Jurgen Doornik, Jennie Castle, and David Hendry) is now in press at the International Journal of Forecasting. open access
[2020-10-10]Removed forecasts from the Chinese scenarios, while investigating possibility to use own history from the first wave.
Added information on the previous peak (if present) to the peak tables.
Local forecasts for England: now dropping last four observations.
[2020-07-01] Modified the short-term model to allow for (slowly changing) seasonality. Many countries show clear seasonality after the initial period, likely caused by institutional factors regarding data collection. This seasonality was also getting in the way of peak detection. As a consequence estimates of the peak date may have changed for countries with strong seasonality.
Added forecasts of cumulative confirmed cases for lower tier local authorities of England. The data is available from 2020-07-02 including all tests (pillar one and two). Only authorities with more than 5 cases in the previous week are included.
[2020-06-29] Tables in April included the world, but not the world as we know it (double counting China and the US). So removed the world from those old tables.
Why short-term forecasts can be better than models for predicting how pandemics evolve just appeared at The Conversation.
Thursday 2 July webinar at the FGV EESP - São Paolo School of Economics. This starts at 16:00 UK time (UTC+01:00) and streamed here.
[2020-06-24] Research presentation on short-term COVID-19 forecasting on 26 June (14:00 UK time) at the Quarterly Forecasting Forum of the IIF UK Chapter.
[2020-06-06] Removed Brazil from yesterday's forecasts (only; last observation 2020-06-05).
[2020-06-04] Data issues with confirmed cases for France.
Added an appendix to the short term paper with further forecast comparisons for European and Latin American countries.
Both Sweden and Iran have lost their peak in confirmed cases. For Sweden the previous peak was on 24 April (daily peak of 656 cases), for Iran it was on 31 March (peak of 3116). For Iran this looks like a second wave, with increasing daily counts for the last four weeks. For Sweden this is a sudden jump in confirmed cases in the last two days, compared to a fairly steady weekly pattern over the previous six weeks.
[2020-05-20] Problem with UK confirmed cases: negative daily count. This makes the forecasts temporarily unreliable.
Updated the second paper.
[2020-05-18] Minor fixes to the improved version of scenario forecasting, backported to 2020-05-13.
[2020-05-13] We now omit countries with fewer than 200 confirmed cases in the last week (25 for deaths).
The short-term paper has some small updates, including further comparisons with other models.
Data for Ecuador are not reliable enough for forecasting.
Switched to an improved version of scenario forecasting.
[2020-05-06] The New York Times is in the process of redefining its US state data. Unfortunately, at the moment only the last observation has changed (e.g New York deaths jumped from 19645 on 2020-05-05 to 25956 a day later). This means the data is currently useless; however it does bring it close to the Johns Hopkins/CSSE count (25626 on 2020-05-06). The aggregate US count is based on JH/CSSE so unaffected. We now use Johns Hopkins/CSSE US state data, including all states with sufficient counts. So the new forecasts cannot be compared to those previously.
A minor change is that we show the graph without scenario forecast if no peak has been detected yet.
[2020-04-29] See our blog entry at the International Institute of Forecasters.
US history of death counts revised in Johns Hopkins/CSSE data.
UK death counts have been revised to include the deaths in care homes. In the Johns Hopkins/CSSE data set, which we use, the entire history has been revised. So forecasts made up to 2020-04-29 cannot be compared to later outcomes. In the ECDC data set only the last observation has changed, causing a jump in the series.
[2020-04-27] Our short-term COVID-19 forecasting paper is now available as Nuffield Economics Discussion Paper 2020-W06.
A small adjustment has been made to the scenario forecast methodology, and will be documented shortly.
[2020-04-24] A summary of our work on short-term COVID-19 forecasting appeared as a voxeu.
[2020-04-17] Bird and Nielsen look into nowcasting death counts in England.
[2020-04-16] Added scenario forecasts to all graphs now. This would now be the preferred forecast for most.
This is the first time with a peak in confirmed UK cases (also for deaths, but this is uncertain because it is at the same date).
[2020-04-10] Updated documentation with better description of short-term estimates and peak determination.
[2020-04-09] Added table with estimated peak dates (if happened) and dates to and since the peak. Note that this can be a local peak, and subsequent re-acceleration (or data revisions) can result in a new peak later.
[2020-04-08] Minor correction to peak estimates. Added table with scenario forecasts.
[2020-04-06] Added a post hoc estimate of the peak number of cases. This needs at least three confirmed observations (four for deaths) after the event. It is based on the averaged smooth trend, and can change later or be a local peak. It is marked with a vertical line with the date label, or a date with left arrow in the bottom left corner of the graph. This is backported to 2020-04-04.
[2020-04-02] Now including more US States, based on New York Times data.
[2020-03-31] Scenario forecasts, based on what happened in China earlier this year, are presented for several countries (line marked with x). Created more plausible 90% confidence bands (dotted line in same colour).
[2020-03-26] Scenario forecasts that are based on what happened in China earlier this year, only for Italy.
[2020-03-24] Our forecasts are starting to overestimate in some cases. This was always expected to happen when the increase starts to slow down. Scenario forecasts that are based on what happened in China earlier this year, but only for Italy and Spain sofar.

Initial visual evaluation of forecasts of Confirmed