Sunday, 11 October 2020

Lies, damn lies and coronavirus statistics

The BBC has to big up lock down and diss the Brazilian President (a right wing-populist, apparently, politics is weird down there):

The number of people to have died from Covid-19 in Brazil has passed 150,000, the country's health ministry says.

Brazil has the second-highest coronavirus death toll in the world, after the US, and the third-highest number of cases after the US and India*. The country also passed five million total infections earlier this week.

President Jair Bolsonaro has been accused of downplaying the risks of the virus throughout the pandemic, ignoring expert advice** on restrictive measures.


Ahem.

Brazil has a population of 211 million. Pro rata, it's death rate was only slightly worse than the UK (705 per million against 629)

In Colombia, the next worst-hit country in the region, 27,495 people have died and there have been 894,300 confirmed cases.

To be fair, Colombia's death rate was indeed lower (542 per million) but not that much better than Brazil's. Also, the countries on or near the equator appear to have fared slightly better (more sunshine).

However the daily number of new cases in Brazil has been slowly falling since it plateaued in the summer, when there were about 1,000 new deaths per day for two months.

Geography lesson - Brazil is in the southern hemisphere. There were chalking up about 1,000 deaths per day from late May to late August (i.e. their winter). Daily deaths have been falling slowly but steadily for the past six weeks. Whether that is because or herd immunity or because sunshine kills the virus, I don't know, but good news is good news whatever the cause.

* The comparison with India is meaningless and misleading in the extreme. They have a population of 1.4 billion and a surprisingly low official death rate of only 78 per million. Their daily deaths crept up steadily (not logarithmically, Neil Ferguson please take note) to 1,200 a day at the peak in mid-September and now appear to be falling again (thankfully).

** Maybe he listened to those experts who said that lock downs were fairly pointless? Or maybe he just accepted that lock down measures would be unenforceable in an inherently unstable country?

18 comments:

George Carty said...

Isn't it the case though that while viral respiratory illnesses are worse in winter in temperate countries, in tropical countries they are worse in the rainy season, which usually corresponds to (astronomical) summer?

Of course this doesn't apply to places within 5 degrees of the equator, where there are usually no seasons at all...

Mark Wadsworth said...

GC, possibly true.

But most of Brazil is well south of the equator. The northern bit is sub-tropical, the bottom bit is temperate.

George Carty said...

MW, SĂŁo Paolo and points south are subtropical (warm temperate) while the whole of the rest of Brazil is tropical (and Amazonia is of course equatorial).

George Carty said...

Just a quick reminder on temperature zone definitions (temperatures in degrees Celsius). Tmax is the mean temperature of the warmest month while Tmin is the mean temperature of the coldest month:

Tropical: Tmin > 18
Sub-tropical: 0 < Tmin < 18, Tmax > 22
Temperate oceanic: 0 < Tmin < 18, 10 < Tmax < 22
Continental: Tmin < 0, Tmax > 10
Polar: Tmax < 10

Mark Wadsworth said...

GC, that's as maybe. But the topic under discussion was Brazil's covid-19 statistics. And it's winter there, however mild.

George Carty said...

My point is that in tropical wet-and-dry climates (like most of Brazil except for the equatorial Amazon basin and the temperate far south) the wet season (when the risk from respiratory viruses is highest) corresponds to astronomical summer.

Mark Wadsworth said...

GC, Brazil is in the southern hemisphere. So do you mean 'winter', from Brazil's point of view?

Lola said...

'Experts' are invariably the problem. Not in any way a solution. (By 'experts' I mean these generalists who seek to plan society and think that they know best for everyone else.

George Carty said...

MW, most of Brazil is of tropical wet-and-dry climate. In those areas the highest risk of respiratory viruses is in the wet season: ie the (southern hemisphere) summer.

Mark Wadsworth said...

L, the bigger issue with "experts" is that they all say different things. With lockdowns, there are two broad camps. One is right, one is wrong. The pol's then listen to the experts who tell them what they want to do anyway.

Bayard said...

Lola, aren't an awful lot of people experts? It's just that in an ideal country, they would be driving taxis, whereas in most countries, they seem to be advising government.

Lola said...

MW. Precisely. 'Experts' who try to organise society always disagree.
B. I think you have to differentiate between experts and expertise. You and I may have 'expertise' in our narrow professional way - be the best taxi drivers say - and that's not at all dangerous. But when it comes to stuff like 'economic planning'.....sigh.

Bayard said...

L, I was thinking more that taxi drivers always know what's wrong with the economy and how to put it right- "What they should do is....."

Dinero said...

Not only is the population of Brazil larger than commonly thought Brazil is also a lot larger. It is the size of Europe from Finland to Poland to Spain and Ireland. More info here -
https://thetruesize.com/

Mark Wadsworth said...

Din. we've done this

It depends where people live. If most live in towns and cities and the rest is empty, then you ignore the empty bits. See also Scotland v England.

George Carty said...

I suspect New Zealand's outstanding success with the virus was owed in part to its location in the southern hemisphere, as the fact that it was summer probably reduced the number of infections in the critical months of January and February (when it was summer in New Zealand). This meant that they still had very few infections by late March, the point when the Overton window had shifted sufficiently to make lockdown an option.

That just makes me wonder though how Argentina was hit so badly, as not only did Argentina also have a strict lockdown, but like New Zealand it also had a geographically isolated location in the southern hemisphere.

Any thoughts?

George Carty said...
This comment has been removed by the author.
Mark Wadsworth said...

GC, re NZ, agreed.

Re Argentina, didn't we have this discussion re Brazil?

The point is, nobody knows for sure why rates were so low in some countries (mainly Far East) with or without lockdown. Or why rates in Brazil have been falling for a couple of months, without lockdown. Or why Sweden fared little worse than many other European countries, despite no lock down.

Nobody knows now and nobody ever will. So these scientists who recommend certain measures and make all these predictions are just making wild guesses.

I wouldn't be surprised if NZ gets its come-uppance later on when it's autumn and winter down there and their death rate catches up to other countries at same latitude. I wouldn't be surprised if NZ has actually made it through and never sees another case again, even if it were to lift lock down today.