I’ve used the concept of “2ab” once before, a day after the Prime Minister used the term in a much lampooned remark, to explain why we need Net Neutrality. I turn to the same concept again to explain why communal harmony is necessary for economic growth.
Some 4-5 days back, a mob entered the house of one Muslim guy who was allegedly cooking beef, and lynched him to death. In response, rather than booking the mob, the police sent meat sample from the victim’s house to “test if he was actually cooking beef” – as if its confirmation as beef would justify the murder.
I’ve mostly been off social media (and hence not fully following the story) since then, but RSS leader Tarun Vijay hasmade some remarks about “lynching on suspicion being wrong“, and star Indian Express columnist Pratap Bhanu Mehta has laid the blame at the Prime Minister’s feet. Mehta writes (HT: V Anantha Nageswaran):
The blame for this has to fall entirely on Modi. Those who spread this poison enjoy his patronage. This government has set a tone that is threatening, mean-spirited and inimical to freedom. Modi should have no doubt that he bears responsibility for the poison that is being spread by the likes of Culture Minister Mahesh Sharma and Vijay — whether through powerlessness or design is irrelevant. But we can be grateful to Vijay for reminding us that the threat to India’s soul emanates from the centre of power, almost nowhere else. It is for that centre, and Modi in particular, to persuade us otherwise.
Now there were two kinds of people Modi appealed to when he came to power in a resounding victory last year – bigots and aspirers. The former hoped that Modi would “teach a lesson to the Muslims”. The latter hoped that Modi would help accelerate economic growth, after a mostly useless and scam-ridden UPA2 government. And Modi might have thought that these two goals are compatible (else it would make no sense to court these two constituencies). Even in theory they are not.
The Gross Domestic Product (GDP), whose growth rate is seen as a bellwether of the economy’s performance, is a measure of the amount of trade. Trade can be external (let’s set that aside for now) and internal. There are many factors that determine the extent of internal trade (trade between the people of the country), but at the margin, it is proportional to the number of possible pairs of people who can trade with each other.
In other words, trade is another of those quantities that follows Metcalfe’s Law, and depends on strong network effects. If the number of people in a place (region or country or state or city) is 
Despite the development of the rule of law and Contract Acts and court-brokered dispute settlements, people typically trade with other people they can trust. In the past, this meant that certain families or communities had a monopoly over trade. Over time, with the development of laws and contracts and courts, this has expanded. Yet, people still hesitate to trade with people they don’t trust.
So what happens when there is communal or caste disharmony? Then you will not trust someone who belongs to another caste or community or religion because of the person’s community (and notwithstanding the person’s personal characteristics). And if you don’t trust them, you don’t trade with them. And what does this mean for the total volume of trade?
It’s time to bring out our 
Communal distrust and the lack of communal harmony ends up restricting the number of possible trading partners for each person, and thus we lose out in terms of the correlation term. In other words, bigotry costs us in terms of GDP growth.
Lastly, even if the government of the day is concerned more about the welfare of one particular community over another, communal harmony makes sense. For by creating distrust, people belonging to the government’s favourite community are denied trade with people of the less favoured community. And this adversely impacts the more favoured community!
Thanks for putting this issue in trade and GDP terms. Perhaps this is the kind of logic that at least some of the bigots will understand- even if they are blind to concerns of ethics or justice.