What’s a logarithmic graph and how does it help explain the spread of COVID-19?

coronavirus CDC

(Credit: Unsplash)

This article is brought to you thanks to the collaboration of The European Sting with the World Economic Forum.

Author: Sean Fleming, Senior Writer, Formative Content


  • Exponential lines showing increases in COVID-19 cases might not always show the full story.
  • While the raw numbers don’t change, the way they are represented can affect perceptions.
  • Logarithmic scale charts can help show the bigger picture.

The coronavirus pandemic is undoubtedly the greatest challenge the world has faced in over a generation. But is the presentation of data about the outbreak leading us to overlook any cause for optimism?

 

There is an alternative to the commonly seen linear graph that could help give a more detailed picture. It’s called a logarithmic graph.

Interpreting information

The most common form of a line-graph has a linear scale. Along the Y axis, the numbers progress in a steady, linear form – 1, 2, 3, 4, or 10, 20, 30 and so on.

What is the World Economic Forum doing about the coronavirus outbreak?

A new strain of Coronavirus, COVID 19, is spreading around the world, causing deaths and major disruption to the global economy.

Responding to this crisis requires global cooperation among governments, international organizations and the business community, which is at the centre of the World Economic Forum’s mission as the International Organization for Public-Private Cooperation.

The Forum has created the COVID Action Platform, a global platform to convene the business community for collective action, protect people’s livelihoods and facilitate business continuity, and mobilize support for the COVID-19 response. The platform is created with the support of the World Health Organization and is open to all businesses and industry groups, as well as other stakeholders, aiming to integrate and inform joint action.

As an organization, the Forum has a track record of supporting efforts to contain epidemics. In 2017, at our Annual Meeting, the Coalition for Epidemic Preparedness Innovations (CEPI) was launched – bringing together experts from government, business, health, academia and civil society to accelerate the development of vaccines. CEPI is currently supporting the race to develop a vaccine against this strand of the coronavirus.

But infectious diseases don’t spread in an even, linear fashion. On a linear scale graph, the rate of growth keeps going up and up – the line can become almost vertical and appear to go on forever. That can create the impression measures like social distancing aren’t working.

On a logarithmic scale, numbers on the Y-axis don’t move up in equal increments but instead each interval increases by a set factor – it’s often 10 but could be a factor of 3 or 350 or 3,500, anything at all. It all depends on what is deemed to be the most effective way of interpreting the data in question. The Richter scale is logarithmic – an earthquake that measures 6 is 10- times more destructive than one that measures 5.

The logarithmic scale is ideal for measuring rates of change, particularly rates of growth, explains mathematician, teacher, and author of The Life-Changing Magic of Numbers, Bobby Seagull.

It “flattens out the rate of growth so it becomes easier to see,”, he says. “On a logarithmic graph of COVID-19 infections, even though the overall numbers are still increasing, you can see the point at which the rate of growth starts to level off when that exponential growth has stopped.”

At that point, the logarithmic scale makes it possible to see when public health measures are starting to have the desired effect.

This is what the COVID-19 situation in China looks like when plotted on a linear graph.

Coronavirus china virus health healthcare who world health organization disease deaths pandemic epidemic worries concerns Health virus contagious contagion viruses diseases disease lab laboratory doctor health dr nurse medical medicine drugs vaccines vaccinations inoculations technology testing test medicinal biotechnology biotech biology chemistry physics microscope research influenza flu cold common cold bug risk symptomes respiratory china iran italy europe asia america south america north washing hands wash hands coughs sneezes spread spreading precaution precautions health warning covid 19 cov SARS 2019ncov wuhan sarscow wuhanpneumonia  pneumonia outbreak patients unhealthy fatality mortality elderly old elder age serious death deathly deadly
The number of cases presented on a linear scale.
Image: Worldometers

And this is how it appears when plotted on the logarithmic scale.

Coronavirus china virus health healthcare who world health organization disease deaths pandemic epidemic worries concerns Health virus contagious contagion viruses diseases disease lab laboratory doctor health dr nurse medical medicine drugs vaccines vaccinations inoculations technology testing test medicinal biotechnology biotech biology chemistry physics microscope research influenza flu cold common cold bug risk symptomes respiratory china iran italy europe asia america south america north washing hands wash hands coughs sneezes spread spreading precaution precautions health warning covid 19 cov SARS 2019ncov wuhan sarscow wuhanpneumonia  pneumonia outbreak patients unhealthy fatality mortality elderly old elder age serious death deathly deadly
The number of cases presented on a logarithmic scale.
Image: Worldometers

Same data, different perspectives

Both charts tell the same story – that China’s coronavirus cases have started to flatline. But the logarithmic graph shows a flattening of the line much earlier because of the way the scale has been compressed. It also makes it possible to fit a large or widespread set of results onto a graph that might otherwise not fit in a linear way.

A logarithmic graph can also help make it clear if the apparent evening-out of the curve started to change. While a linear curve would keep on pushing ever higher regardless, the logarithmic graph would highlight any substantial changes to the trend – whether upward or downward.

It’s an approach that is often preferred when there are huge numbers involved and a linear scale would just produce a dramatic-looking exponential curve.

the sting Milestone

Featured Stings

Can we feed everyone without unleashing disaster? Read on

These campaigners want to give a quarter of the UK back to nature

How to build a more resilient and inclusive global system

Stopping antimicrobial resistance would cost just USD 2 per person a year

EU foreign investment screening mechanism becomes fully operational

How populist and xenophobic movements in the EU tear apart European businesses and startups

FROM THE FIELD: Persons with disabilities bike towards sustainability

Six months into DR Congo’s deadliest Ebola outbreak, top UN official praises ‘brave’ response effort

Euro celebrates its 20th birthday

Yanukovych attempts a violent and deadly cleansing of Kiev’s center

Things are bad and getting worse for South Africa. Or are they?

Pride in practice: Equality in access to health services for the LGBT community in a third-world country

How the world can ‘reset’ itself after COVID-19 – according to these experts

Why this is the year we must take action on mental health

4 things ISPs can do to reduce the impact of cybercrime

Statement by Cecilia Malmström, Member of the EC in charge of Trade, on the successful conclusion of the final discussions on the EU-Japan Economic Partnership Agreement (EPA) – Brussels, 08 Dec 2017. (Copyright: European Union; Source: EC - Audiovisual Service; Photo: Georges Boulougouris)

The EU and Japan seal free trade pact that will cover 30% of global GDP

We need a global convention to end workplace sexual harassment

This is how we make cancer care sustainable and available for all

This is the biggest risk we face with AI, by Google CEO Sundar Pichai

International tourism is set to plunge by 80% this year – but some regions could recover more quickly

TTIP is not dead as of yet, the 15th round of negotiations in New York shouts

Election 2019: New, Updated seat projection for new Parliament

Tuesday’s Daily Brief: Libya civil war, African displacement, global trade tensions, terrorists’ children ‘secretly detained’, and more

Vaccine hesitancy: a pregnancy related issue?

What’s everyone talking about at Davos 2020?

The five stages of the Chief Digital Officer – and why they often fail

World must do more to tackle ‘shadowy’ mercenary activities undermining stability in Africa, says UN chief

Young? You should work out the entrepreneurial heart before the mind

COVID-19: Budget MEPs call for quick progress on post-2020 contingency plan

EU budget 2019 approved: focus on the young, innovation and migration

EU supports recovery and resilience in Nigeria with additional €50 million

India m2m + iot Forum Hosts Successful 4th Editions of India Smart Cities Forum and India Smart Villages Forum

Novartis and Johnson & Johnson to deprive Europeans of their right to Health

Who’s promised net-zero, and who looks likely to get there?

It’s time to ‘eliminate the scourge of conflict-related sexual violence’, urges UN chief

European Council: Choosing new leaders for the EU betrays efforts for a wider arrangement

Global Citizen – Volunteer Internships

MEPs spell out priorities for the European Central Bank and on banking union

UN chief appeals to G7 leaders for ‘strong commitment’ and political will to tackle climate emergency

People talk less now than during the Cold War, says Merkel at Davos

Conflicting statistics and bad banks haunt the Eurozone

The four top Americans who flew to Europe perplexed things about Trump’s intentions

This new initiative aims to make cybercrime harder – and riskier – to commit

Chauvinism and xenophobia will lead to global assertiveness and more wars

At last a good price for the Greek debt!

Costa Rica has improved its foreign bribery legislation but must strengthen enforcement and close legal loopholes

South Sudan’s women caught up in ‘futile man’s war’ UN gender equality chief

Climate change update: consistent global actions urgently needed as we are running out of time

SDG progress ‘in danger’ of going backwards without change in direction, new UN report reveals

Nicaragua ‘crisis’ still cause for concern amid murder, torture allegations: Bachelet

MWC19 Wrap Up, in association with The European Sting, GSMA’s Brussels Media Partner for the 6th Consecutive Year

The global issue of migration in 2017

We underestimate the power of data at our peril. This is why

This fascinating map shows how food moves around the US

DR Congo: Strengthened effort against Ebola is paying off, but insecurity still major constraint – UN health agency

Further reforms will move Slovakia toward a more innovative and inclusive society

European Parliament marks EU accession prospects for Serbia and Kosovo

IMF: When high yield goes boom

Female leaders warn about the erosion of women’s rights

An analysis of the impacts of climate change on human health

Why responsible consumption is everyone’s business

Here’s what keeps CEOs awake at night (and why it might be bad news for your next job)

Boeing subsidy case: World Trade Organization confirms EU right to retaliate against $4 billion of U.S. imports

Religious violence is on the rise. What can faith-based communities do about it?

More Stings?

Advertising

Speak your Mind Here

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s