Quarantine, Test and Trace and BODMAS

Episode Summary

Executive Summary: This episode of More or Less examines whether UK COVID testing and tracing figures were misleadingly inflated by double counting, challenges claims that most COVID deaths were imminent anyway, compares infection prevalence to assess the logic of quarantining arrivals to the UK, investigates pangolin trafficking claims, and finishes with two maths puzzles explained by Jen Rogers.

Main Topics: Test and trace numbers and double counting (Priority: 5/5): The programme digs into government testing and tracing figures and finds a mismatch between reported positive tests and people actually referred to test and trace, largely explained by repeated tests being counted as separate cases. Are COVID deaths mostly people who would have died soon anyway? (Priority: 5/5): Tim Harford explores claims that COVID-19 mortality is exaggerated because many victims were very elderly or had comorbidities, using actuarial evidence to show average remaining lifespans were often years, not months. Should the UK quarantine incoming travellers? (Priority: 4/5): Ruth Alexander and Tim Russell compare active infection prevalence across countries to assess whether the UK’s quarantine policy makes sense, concluding the UK still had comparatively high prevalence, though not higher than some countries. Pangolins as the most trafficked mammal (Priority: 3/5): The episode examines claims that pangolins are the world’s most heavily trafficked wild mammal, explaining how seizure data are converted from scales to animal counts and noting broader wildlife trade is dominated by timber and fisheries. Mathematical puzzles and Bodmas (Priority: 2/5): Jen Rogers explains order of operations using a simple arithmetic example and then solves a clock-chiming puzzle by distinguishing between chimes and the gaps between them.

Key Arguments: Government daily COVID case figures were inflated by double counting because the same person could be tested more than once and counted multiple times. Of the 12,600 positive tests referred to test and trace in England, more than 4,000 were duplicate tests, leaving about 8,100 actual people to trace. ONS community surveillance, not daily testing totals, was the better estimate of true prevalence; the testing system missed cases rather than simply failing to trace them. Claims that most COVID victims would have died within months are not supported by actuarial data; average life expectancy at age 80 remains many years. Comorbidities do not imply near-term death because older people commonly have multiple comorbidities, yet still have substantial remaining life expectancy on average. COVID can bring deaths forward temporarily, as seen after heatwaves and flu seasons, but there is no guarantee excess deaths will simply be offset later. Risk from COVID is highly age-skewed: older adults, especially care home residents, faced much higher mortality than the general population. The UK’s quarantine policy should be judged against global prevalence; despite falling infection levels, the UK still ranked near the top of countries with large populations. Pangolin trafficking estimates rely on converting seized scale weights into animal counts using species-specific scale numbers and representative sampling. Many viral social-media math puzzles exploit misunderstanding of order of operations; BODMAS resolves them by prioritizing brackets, then orders, then division/multiplication, then addition/subtraction.

Data Points: People referred to test and trace (28 May-3 June): 8,117 - Government figure for England’s test and trace referrals Daily reported positive cases over same period: 13,417 - Slide shown in government briefings; included double counting Difference between referred cases and positive cases: 5,300 - Gap explained partly by devolved nations and mostly by duplicate tests Cases from Wales, Scotland and Northern Ireland: about 800 - These were outside England’s test and trace system Duplicate tests among England positives referred to test and trace: more than 4,000 - Department of Health and Social Care said many lab-confirmed cases were repeat tests ONS estimate of people with virus in community in England: 33,000 - Estimated for late May/early June, excluding hospitals and care homes Age 80 average life expectancy: 9 years for males; 10 years for females - ONS projections used to challenge claims of imminent death Share of excess deaths aged 75+: three quarters - Used to explain why COVID deaths are concentrated among older adults Older people with comorbidities: 4 in 5 people aged 80+ have 2 or more; 90% have 1 or more - Shows comorbidities are common and do not by themselves imply short life expectancy ICU patient average age: 60 - Stuart MacDonald noted many ICU patients still had decades of life expectancy ahead Crude mortality rate from COVID in England and Wales: around 1 in 1,000 - Based on roughly 60,000 excess deaths in a population of around 60 million Mortality risk for age 85+ relative to under 50s: about 500 times as much risk - Illustrates steep age gradient in COVID mortality Risk for age 50-64 compared with population average: around half the average risk; about 1 in 2,000 - Age-specific estimate from actuary Stuart MacDonald Risk for age 75-84 compared with age 50-64: around 11 times as much risk; about 1 in 200 - Shows risk increases sharply with age Care home share of excess deaths: almost half - Care home residents accounted for a large fraction of deaths Estimated death risk for care home residents aged 75-84: around 1 in 13 - Derived from observed deaths in care homes Community death risk for 75-84 after excluding care homes: about 1 in 300 - Substantially lower than the care-home-adjusted risk Countries with higher active infection prevalence than UK: 6 countries above the UK among nations over 5 million population - Used in discussion of quarantine policy UK rank in active infection prevalence: about 7th globally - Among countries with populations over 5 million Top prevalence countries: Brazil, Mexico, Peru, Sweden, Chile, Saudi Arabia, UK - Countries with highest estimated current infection prevalence at time of update Pangolin seizure estimate: up to around 20 tonnes of pangolin parts intercepted each year - Traffic/Dr. Richard Thomas estimate Pangolins seized over 15 years: approaching 1 million - Estimated from international trade seizures Tiger poaching figure (2000-2015): 758 - Compared with pangolin seizures to contextualize wildlife trafficking African elephants poached (2000-2015): around 300,000 - Broader wildlife trafficking comparison Clock chime puzzle: 8 chimes at 8:00 = 35 seconds; 12 chimes at noon = 55 seconds - Illustrates reasoning with intervals rather than number of chimes

Pivotal Quotes: "The government says 8,117 people were referred to test and trace between the 28th of May and the 3rd of June. But the daily figure for positive cases of COVID-19 over the same period ... adds up to 13,417." — Kate Lamble: Explaining the mismatch in official testing and tracing figures "I don't agree with that claim. It is true, of course, that a number of the people who have died of COVID-19 would have died later this year, perhaps next year. But to assert that a majority would have died within the next three months is not supported by any of the data I've seen." — Stuart MacDonald: Rejecting the claim that most COVID deaths were imminent anyway "The UK currently ranks about seventh in the world in terms of what proportion of people are thought to be infected right now." — Ruth Alexander: Assessing whether quarantine of incoming travellers makes epidemiological sense

Implications: The episode suggests official COVID metrics must be interpreted carefully, especially where double counting and incomplete tracing distort headlines. It also argues for evidence-based risk assessment on deaths and travel policy, while reminding listeners that viral statistics, trafficking claims, and even simple arithmetic can be misleading without proper methods.