SDG 10 is the one that most people assume they know what it’s about, but actually don’t. For various reasons, we think about reducing inequality in the context of our personal identities. It’s no wonder, since that is how we personally experience inequality. And through human empathy, that is also how we feel its effect on another. Even the summary description at the UN website implies it.

Except that the targets list (some of which seem to duplicate targets already in other SDGs) suggests a different emphasis. While receiving a sense of security in society is a human need, equality at this personal level is not what this SDG is really about. Similar to SDG 9, SDG 10 is about inequality in the context of societal goals to continue providing for basic needs. But the societal goals are about maintaining harmony and belonging as a society grows more prosperous.

This is important for global sustainability because a society with deep inequalities is forced to spend a lot of resources to deal with dissent, or have it leak away through migration and brain drain.

Why does inequality exist in society (I mean, fundamentally)?

Small, simple societies usually have less problems with inequality, compared to large nations with complex civilisations. The reason can be inferred from understanding SDG 9. When a society needs to provide for a lot more people, and creates infrastructure and industry to do so, division of labour is inevitable. With it, emerges inequality.

The reality is, most societies contain inequality. Some even have it embedded in societal structures; common examples include monarchies. But even liberal democracies have inequality in practice. This is why this SDG isn’t called “no inequality” or “eradicate inequality”, but “reduced inequalities”.

The strange thing is, from my travels I observed that not all types of inequality are perceived negatively. Even when they are, the reasons may differ, thus the solutions for one culture won’t work in another. The types of inequality people reject around the world can’t really be understood just by reading the UN description. It requires knowledge of the culture’s historical context. And I think that we can better understand why, and what SDG 10 is really about, when we understand that issues of inequality aren’t objective, but are about relationships within a social contract.

Inequality in the context of a social contract

At the fundamental level, a society is formed to provide for the basic needs for the most number of people. This core group is who we call the ‘mainstream’. In order to form the society, it has to decide the conditions for belonging. Prior to modern state citizenship, common examples include assimilating into the mainstream language and culture (in ethnicity-based societies), or pledging allegiance and obeying the laws of the king (in plural societies).

Then, as now, what kind of inequality is tolerated by members depends on whether it’s seen as a fair part of the society’s social contract. This is usually because there is a trade-off in the culture that squares it out. Over the generations, healthy societies may expand its social contract as they inevitably pursue the greater human needs of transcendence. But in general, the mainstream is privileged, and the logic is simple. If the mainstream can’t meet its basic needs, there will be no society left to provide for anyone.

Providing security and belonging is normally part of a society’s social contract. When it excludes members from meaningful belonging and participation, it may not be a problem at first. But if the inequalities worsen, or if it is perceived to no longer be fair, trust in the social contract breaks down, and so will the society.

That is why the targets related to inequality within countries go beyond reducing the experience of harassment. However, similar to gender equality, equality within a given social contract implies a relationship, this time between a society and its members. Improving a sense of inclusion in society inherently involves a societal conversation and negotiation that should only take place within the society, since outside interference will also result in losing the society or its sovereignty.

Inequality within global society

Another reason why this SDG is poorly understood can be seen in how the majority of its targets actually relate to inequality between countries, rather than within countries, suggesting that the greater portion of sustainability issues related to inequality lies in the global society – yet the UN summary description appears to give weightage to national society.

In fact, some of the reasons why domestic inequality exists in many global south countries, is not due to their own original societies. They are a direct result of colonisation, i.e. another society removing their ability to decide admission of members, and then afterwards having to absorb large numbers of new members who signed up for, or are raised to expect, a different social contract than the one that actually suits the mainstream.

Many countries today, even former colonial powers, ended up with overlapping social contracts: one being citizenship to the state, which is not always the same as the second, which is admission to traditional society. Trying to push SDG 10 targets while skipping the necessary societal conversation, and ignoring the role of third party societies in creating or worsening the problem, is now resulting in the rise of far right nationalism around the world.

And finally, just as it does within countries, inequality between countries in the global society also leads to erosion of trust in the global social contract in the same way. And since trust is necessary for collaboration to solve global sustainability problems, we can expect efforts to negotiate a better international social contract to continue, as well as experiments to build alternative global structures that better provide mutual security for the global mainstream.