It was the renowned Jewish social scientist, Professor Steven M Cohen, who first taught me the insight about 20 years ago. He asked me a simple question: if I could choose one variable to predict whether someone was likely to have a strong Jewish identity, what would it be? I offered my suggestions — parenting, educational background, synagogue membership, having Jewish friends, etc. He nodded at them all. But then he told me I’d missed one— perhaps the most fundamental one of all. I racked my brains but couldn’t think what it could be. After a prolonged pause, he gave me the answer. The best scientific indicator to use is their post-code.

Over time, I have come to appreciate his insight. Geography matters. If we live in an area with a sizeable Jewish population, we have access to a wide variety of Jewish services and a network of Jewish friends. We have numerous opportunities to engage in Jewish activities and interactions simply because they exist on our doorstep. Synagogues, Jewish schools, cultural activities, kosher butchers, bakers, restaurants and shops will all be close by. And, in most cases, we will have chosen to live in these neighbourhoods, at least in part, due to our desire to have access to all of this.

The data support his claim. As a general rule, Jews who live in “Jewish’’ neighbourhoods have stronger Jewish identities than those who do not. It’s not always the case, of course — it’s possible to maintain a Jewish identity in places where relatively few Jews live — but the data show clear distinctions between, for example, Jews in Barnet and Jews in Buckinghamshire. Collectively, on a whole host of indicators, Jews in Barnet are, quite simply, more Jewish.

But in the context of the coronavirus pandemic, our geographical choices also appear to have inadvertently affected the likelihood of us contracting Covid-19. Despite ongoing questions about the quality and consistency of the public data being generated, we can use those data to draw some tentative conclusions about what might be happening in the Jewish community.

Public Health England produces daily counts of confirmed cases of Covid-19 in every local authority in England. In some places —particularly in LAs across London — the rate of infection is high. In others — such as Rutland, the Isle of Wight, Somerset — it is very low. We also know precisely how many Jews live in each LA, and the proportion of people in each that is Jewish. Using these data together, we can estimate how many Jews might be expected to have contracted Covid-19 simply by virtue of where they live, and disregarding any other possible factors that might be involved.

Due to geography alone, Jews may be considerably more likely than average— possibly by as much as 50-80 per cent at present — to become infected. In simple terms, there are certain areas where the rates of infection are high; a few of these happen to be where Jews live; so Jews, like others living in those neighbourhoods, are statistically at a higher risk than average of picking up the infection.

Of course, the likelihood of Jews contracting the virus is not only a matter of geography; our socio-economic profile, health profile and our ability or desire to socially distance also matter. But, at this stage, we don’t have sufficient data to make those assessments.

We can, however, consider our age profile, and as with geography, government data indicate that a disproportionately high number of Jews may die from Covid-19, simply because, compared to the population as a whole, British Jews are much more likely to be elderly.

So, in brief, both our age and our location work against us. The key question going forward is whether or not these factors will be compensated for by other factors, some of which are actually known to work in our favour.

But the most important thing in these findings is that any disproportionality we see in the numbers of Jewish deaths, if indeed we see it at all at the end of this, cannot be simply or loosely blamed on non-compliant behaviour within any specific part of our community. On the contrary, a key reason seems to be the simple misfortune of our demography — we just happen to live in certain postcodes and have high numbers of elderly people within our community. As Professor Cohen said years ago — the most important variables to consider are not always the ones that most readily spring to mind.

Jonathan Boyd is Executive Director of the Institute for Jewish Policy Research (JPR).