It’s happened again.

Three people die in a bombing at the Boston Marathon, and it completely dominates news coverage for days.

Around the same time, about 50 people die in a wave of bombings across Iraq and the coverage is...well...rather less.

A week or so later, more than 200 people die in an earthquake in China. Again, this terrible tragedy, with its huge loss of life, attracts far less media coverage than Boston.

We all know that every story is different and there are a range of factors that influence how newsworthy it is, but whenever such stark differences emerge, difficult questions also emerge.

Why does one life matter more than another? Aren’t all lives of equal value? By seeming to attach greater significance to an American death than an Iraqi death or a Chinese death, are we betraying our biases? Is our value system skewed or even racist?

In my view, there are really two questions here, and the second one is far more interesting than the first.

The first question to answer is why one death seems to matter more than another, and I think that shouldn’t be a difficult question for a journalist to answer.

There was an important piece of journalistic research done in 1987 by, among others, Pamela Shoemaker, who went on to become a senior communications professor at Syracuse University in New York.

In that article – a monograph with the sexy title Building a Theory of News Content – Ms Shoemaker identified eight key factors that determine how much coverage a story gets. It was an attempt to crack the age-old question of what constitutes “newsworthiness”, that nebulous concept we all rely on to determine whether a story is worth covering or not.

Those eight factors include things like timeliness, importance, controversy and novelty, but the relevant one for this discussion is proximity. Shoemaker defined “proximity” this way:

“the closer an event takes place to the intended audience, the more important it is”

Of course, this is hardly new or surprising. Fourteen years earlier, in 1973, another group of journalism academics had noted the same phenomenon, only they called it “relevance”. They explained it then by saying that “a California earthquake is almost always more relevant to a West Coast audience than to an audience in Calcutta”.

So it’s not about whether one human life is worth more than another. It’s about the notion of “proximity”, the fact that audiences care more about issues they feel close to, events they can relate to and identify with. Proximity doesn’t have to be just about geography, either. There are many different ways that one can feel ‘close’ to a story.

That shouldn’t be controversial or problematic. To reduce it to a universal concept beyond the news business, it is undeniably the case that I will be more affected by a tragedy affecting my own family than someone else’s family, and a story involving someone I know (including, yes, their death) will affect me more than a story involving someone I don’t know. And if I am affected more, I will talk about it more, think about it more and want to know more about the circumstances. That’s not because I value one life over another, but because one has greater impact, greater relevance. More proximity, if you like. I don’t think that is anything one needs to feel guilty about, or apologise for.

But that leads us to the second question, which I think is a more interesting one to ponder in the wake of the Boston marathon.

If it is true that stories from the US seem to us to have more “proximity” to our audiences – and I think it is clearly true – then why is that, and how long will that continue?

There is a strong argument to suggest that what happened in Boston resonated far more with an Australian audience because we identified with the circumstances. Melbourne or Sydney is not that different to a town like Boston. The people, the streets, the community. That perceived sameness creates links and connections that provide the sense of relevance and proximity.

But look at this interesting map, based on census data, of the country of birth of modern Australians.

That’s our audience, the people on whose behalf we decide things like proximity and relevance.

It’s a diverse and changing group, and when you look at the “hot spots” around the world, the browns and the reds where growing numbers of Australians come from, it’s increasingly not Western Europe or the United States. The big growth areas are China, the sub continent and Asia.

The largest growing communities in Australia are currently from India and China. Around 70% of overseas born Australians now come from non-English speaking countries.

The growing diversity of the Australian community means it is more and more challenging to assess which stories resonate the most with ABC audiences.

There are no easy answers to these things. When the Australian media decided the Boston bombings were a much bigger story for our audiences than the Baghdad bombings, I am sure they were right. There are all sorts of cultural, historic, issues-based and practical reasons why that’s the case.

But there is really only one way we can ensure we are on firm ground when we make these calls, and that is to stay connected with our audiences, to make sure that we draw our reporting ranks from all sections of the community, and to listen to the feedback and responses we get from those who watch our News. There may be a great many people in our audience with very different priorities, interests and perceived ‘proximities’ than our own, and we would do well to remember that.