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The meaning of R
Sustained R, starting from 1,600 daily new cases (dnc):
R=0.97
halving time (ht)=3 months 1,020 dnc in 2 months
R=0.8 ht=12.4 days 60 dnc in 2 months, zero in 4.5 months
R=0.6 ht=5.4 days ZERO dnc in *2 months*
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Sustained R, starting from 1,600 daily new cases (dnc):
R=0.97
halving time (ht)=3 months 1,020 dnc in 2 monthsR=0.8
ht=12.4 days 60 dnc in 2 months, zero in 4.5 monthsR=0.6
ht=5.4 days ZERO dnc in *2 months* 1/
The meaning of R
Sustained R, starting from 1,600 daily new cases,
Toll of the first 2 months:
R=0.97 76,300 cases 1,220 deaths
R=0.8 28,400 cases 450 deaths
R=0.6 13,300 cases 210 deaths
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Sustained R, starting from 1,600 daily new cases,
Toll of the first 2 months:
R=0.97
76,300 cases 1,220 deathsR=0.8
28,400 cases 450 deathsR=0.6
13,300 cases 210 deaths2/
Toll of subsequent months (after the first 2 months):
R=0.97 : a lot of cases & deaths, high risk of exponential surge & next lockdown
R=0.8 : some cases and deaths, high risk of exponential surge & next lockdown
R=0.6 : NOTHING
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R=0.97 : a lot of cases & deaths, high risk of exponential surge & next lockdown
R=0.8 : some cases and deaths, high risk of exponential surge & next lockdown
R=0.6 : NOTHING
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What gives which R value
R=0.97
some restrictions
R=0.8 demi-lockdown (e.g. businesses closed but schools open, insufficient travel restrictions, etc.)
R=0.5-0.65 regular lockdown (e.g. 1st wave Austria, New Zealand, 2nd wave Melbourne/Victoria Stage 4/3)
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R=0.97
some restrictionsR=0.8
demi-lockdown (e.g. businesses closed but schools open, insufficient travel restrictions, etc.)R=0.5-0.65
regular lockdown (e.g. 1st wave Austria, New Zealand, 2nd wave Melbourne/Victoria Stage 4/3)4/
For reference, Alberta's halving time in the 1st wave was 7.8 days (an equivalent of R=0.7 )
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Extra ingredients:
Addressing aerosol transmission of COVID-19
Vaccine
will additionally lower the R
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Addressing aerosol transmission of COVID-19 Vaccine will additionally lower the R
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Thank you @Imgrund for answering my questions and explaining the relationship between R value and halving time! 
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