Ben Lowry: If this island must be different to Great Britain in its response to Covid-19, then why not come out of lockdown faster?

That the island of Ireland has been less badly hit by the virus than the island of Great Britain, and so should move fastest out of lockdown.

But insofar as we can say anything about the differential spread of coronavirus, we can probably say that both sides of the border have been less badly hit than the larger island across the Irish Sea.

Numerous medical and statistical experts have said that it is too early to make detailed comparisons about the spread of the virus between different nations. In fact, they say, it will be years before there is a detailed understanding of what has happened in each country.

This is due to things such as different levels of testing, different methods of recording deaths and varying ways of collating the data.

Internationally, for example, Belgium is said to be worst for deaths in Europe partly because it is the most transparent and includes suspected deaths linked to Covid-19.

Even within the four home nations of the United Kingdom, there are differing ways of measuring what is happening.

None of this has stopped Irish nationalists and their expert apologists from incessantly comparing outcomes in the UK to the Republic of Ireland (incidentally, has anyone ever come across a medical expert who seems to evangelise on behalf of the UK’s record and approach?).

Not only has the UK-Ireland comparison been made relentlessly, it was made six weeks ago when it was even more inappropriately early and prone to error.

Yet while it is too soon to make detailed comparisons, broad trends have been apparent for weeks, showing that some countries are far more badly hit by Covid-19, for reasons that are often unclear.

One thing that has been stark is the discrepancy between England and the other parts of these islands.

Yet this is not often mentioned, because the UK is considered a single unit for international counting comparisons.

However, if you think of a five-part British Isles, then England has far higher deaths per person than any of the other four parts.

Deaths in Scotland, Wales, Northern Ireland and the Republic are all set to end up (at the end of this first wave of the pandemic) somewhere in the range of 300 to 400 fatalities per million people.

Deaths in England will be 600+.

At the moment the Republic of Ireland (RoI) has a slightly higher death toll than NI, but when care homes are added to the latter it might end up lower.

Both RoI and NI are a bit behind Wales and Scotland, but not much.

The are two plausible factors for the differences.

The first is population density.

England is far more packed than the other four parts, with a massive 432 people per square kilometre.

Wales is next, 148 per squ km.

Then NI on 133 per squ km.

This is almost twice as densely populated as the Republic of Ireland (around 70 per squ km), and Scotland (67 per squ km).

If England was a nation state it would be one of the 10 most densely populated on Earth (if city states and micro states, which distort the tables, are discounted).

Critics of the population density theory are right to say that the global spread of Covid-19 is much more complicated than population density. Some nations with the best outcomes are very densely populated, such as Taiwan and South Korea.

But when you exclude a small number of competent nations that responded fast, such as those two and Germany, there is a striking correlation with population density. Netherlands and Belgium are badly hit by the virus, and Europe’s most densely populated countries.

The most densely populated states of the US — New Jersey, Rhode Island, Massachusetts, Connecticut, Maryland, Delaware, New York — are all at the top of the worst hit Covid states.

(In all of the above countries and states I am referring to per capita deaths, which crucially takes account of population size — not density — as opposed to the absolute death tolls, which are meaningless in the absence of reference to overall population size.)

The second plausible factor in the British Isles differences is the two islands — that Covid-19 arrived a bit later on this island, which gave us more time to prepare.

This is not to say that policy made no difference. The Republic ramped up testing faster than the UK and it closed the St Patrick’s Day parades when England did not stop events like Cheltenham. But it is also possible that it closed schools too early and is reopening them too late.

One day we will better understand all the reasons for the differing outcomes.

Yet this island is coming out of lockdown very slowly, in several respects behind England. Northern Ireland’s slow exit plan has been almost forced to mirror Ireland’s.

Denmark has one of the lowest death tolls in Europe and is now one of the fastest out of lockdown.

It often seems that there a cross-border determination here to be seen to be different and more cautious than Boris Johnson because he is depicted as a reckless Tory.

• Ben Lowry (@BenLowry2) is News Letter deputy editor

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