So, one of the interesting things about Ireland is that part of the Island is still managed by the UK.

So in some sense, we actually have an appropriate control for your assertion that its down to population density.

In general, the data does not support your assertion around population density, as the Republic of Ireland has (post lockdown) a rate of 88.5 per 100k, whereas Northern Ireland has a rate of 2788 per 100k.

Source 1: https://www.ecdc.europa.eu/en/cases-2019-ncov-eueea Northern ireland: https://www.health-ni.gov.uk/covid-19-statistics

So, in this particular case, it seems unlikely that population density is driving the differences.

I do agree that raw country comparisons can often mislead, but i stand by my original points.

Source 1 is showing a sum for the trailing 14 days. Source 2 is showing cumulative statistics for the entire pandemic. Your source 1 even says the UK as a whole is 372.1 per 100k.

Northern Ireland has a rate of 133 per 100k, for the last 7 days.

The figure you've quoted is close to the total for all of Northern Ireland (2,505) for the last 7 days.

I thought that was too high, cheers for correcting me.

I think the general point is still valid though, as there's a substantial difference between the two regions.

Northern Ireland government is an utter mess, the two useless cretans in Stormont couldn't tell their arse from their elbow. McGuinness and Paisley got on better than those other two and they had every reason to hate each other.

Northern Ireland also has loads of inter UK travel every day, I know people who were at some points commuting from London to N.Ireland.

There's more flights (and capacity) between London and Dublin than between London and Belfast.

Yeah, agreed.

I didn't want to get into a whole explanation for someone, just to make a point about density not being the primary driver in this case (although it definitely has an impact).

Australia on average is very sparsely populated. However, it's also one of the most urbanized countries in the world, and places like central Sydney are hardly "very sparsely populated".

Density is complicated. On one hand, raw population per square kilometer is obviously a useless metric for epidemics. It's trivial to understand that taking a small country with a few cities, and adding a vast uninhabited area will drive people/sq.km towards zero without actually changing the actual density where people live (See Canada, Sweden, Australia and many others).

So it's not people per area. Perhaps a better measure is "mean distance" between people? That means Australia is pretty dense because most people live in dense areas. Urbanization is obviously a much better metric than raw density.

But this also misses another important factor: Australi, and Sweden (which are sparse but urbanized so low pop/sq.qm but low mean distance), unlike the UK is pretty "disconnected". There are clusters with high density, but they are separated by areas of low density.

It's likely better in an epidemic to have 3 cities with 1 million separated from each other, than 30 cities with 100k people each, where people in each cities visit/commute to the next 5 cities. That's what some places like UK/Netherlands/Belgium have. They are extremely dense in the sense that it's always close to the next population center. There are no natural borders or empty spaces. People from city A work in town B, and some fraction of people in town B work in city C and so on. Towns A and Z are connected by just a few days worth of normal commute for thousands of people.

There are some fairly empty bits of the UK (e.g. there is greater area of peat bogs (9%) than is built up (6%)) - which means the bits of the UK where people live are even more densely populated than you might expect:

https://www.sheffield.ac.uk/news/nr/land-cover-atlas-uk-1.74...

The CBD of Syndey is still nowhere near what it was pre covid. Most of the large tech companies are still work from home.

I commute to the CBD every day and it's nowhere near like it was, I can get a seat on the train, even with distancing. I couldn't even get a seat during rush hour before covid.