The Mathematical Derivative of the Torah

By Kampamba Shula | Opinion

Key takeaways

Kampamba Shula argues that Zambia’s tax system, inherited from British colonial administration and layered through six decades of legislation, still runs without a philosophy of its own.
The tithe offers a 10 percent benchmark for broad-based taxation, with extra taxes justified only by harmful consumption, environmental damage or greater capacity to pay.
2 Kings 23:35’s phrase “according to his assessment” is an early case for taxing people by circumstance rather than uniformly.
Welfare success should be counted by how many people graduate into self-sufficiency, not how many are enrolled; cliff-edge benefit cuts can make earning more a loss.
Churches need not be taxed, but large ones enjoying tax privileges should report publicly on the schools, clinics and feeding programmes those privileges fund.

There is a contrarian argument I have been thinking about for some time: should churches in Zambia be taxed, or at the very least be required to report transparently on their community impact and social services? It is a provocative question, particularly in a country where religion occupies an important place in public life. But my argument is not really about churches. It is about something deeper: what philosophy should underpin Zambia’s tax and social welfare system?

The tithe as a benchmark, not a blueprint

I believe Zambia has not fully explored the economic mathematics contained in the Bible, particularly the Old Testament and the Torah. I am not talking about Zambia being a Christian nation, nor am I making a theological argument about the New Testament. I am interested in the economic principles embedded in the older texts: taxation, redistribution, poverty, obligation and social responsibility. And one number appears repeatedly as an interesting starting point: ten percent.

The biblical tradition places considerable importance on the tenth, or tithe. There is something intuitively interesting about this number. We count using ten fingers and ten toes, and our modern numerical system is decimal. The tithe represents a simple proposition: contribute a defined proportion of what you have. Of course, this does not mean modern governments should simply copy an ancient religious practice and impose a universal 10 percent tax. But it raises an interesting economic question: what should be the base rate of taxation, and at what point does taxation become economically counterproductive?

My own view is that 10 percent provides an interesting philosophical benchmark for broad-based taxation, with additional taxes justified where there are clear economic reasons, such as harmful consumption, environmental externalities or greater capacity to contribute. The mathematics can be debated. Economists can construct models showing how different tax rates affect incentives, revenue and economic activity. But before we get lost in the mathematics, there is another principle worth considering: taxation according to circumstance.

“According to his assessment”

In 2 Kings 23:35, we encounter an account of taxation under King Jehoiakim: “He exacted the silver and gold from the people of the land, from every one according to his assessment.” The phrase that interests me is “according to his assessment.” A tax system inevitably has to make judgements about capacity to pay. A farmer, a salaried worker, a multinational corporation and a wealthy investor do not have the same economic circumstances. Treating them identically is not necessarily fairness. This is why progressive taxation exists. The question for Zambia is whether our tax system has found the right balance between raising revenue and preserving the incentives required for investment, entrepreneurship and economic growth.

An inherited tax code, not a designed one

Much of Zambia’s modern tax architecture has roots in the British system inherited at independence and subsequently developed through successive pieces of legislation. There is nothing inherently wrong with borrowing institutions. Countries have always learned from one another. But more than six decades after independence, Zambia should be asking whether its tax system adequately reflects the structure of the Zambian economy. Our Income Tax Act is an extensive body of legislation, including domestic taxation provisions as well as a large number of provisions relating to international taxation and double taxation agreements. The complexity itself creates a problem. Many citizens and small businesses interact with the tax system without fully understanding the legislation governing them. Some taxpayers may not even realise that the law contains provisions that can reduce their tax burden through allowable deductions, rebates and other mechanisms. A tax system should not be designed so that only specialists can understand how it works.

Tzedaka: justice, not charity

There is another lesson from the Torah that Zambia should take seriously: the obligation to support those who are vulnerable. The existence of poverty is not an argument against social welfare. A nation will always contain people with different levels of wealth and economic opportunity. The challenge is how society responds to that inequality. The Jewish concept of Tzedaka is particularly interesting in this regard. Derived from tzedek, meaning justice, Tzedaka is often understood not simply as charity, but as an obligation to pursue justice and support those in need. The Torah establishes mechanisms for supporting the poor and redistributing resources. Deuteronomy 16:20 states, “Tzedek, tzedek you shall pursue.” The repetition is striking. Justice is something to be actively pursued.

That principle has considerable relevance to modern social protection policy in Zambia. The problem with social welfare is not that governments support poor people. The problem arises when welfare systems are designed in a way that makes it difficult for people to escape them. Consider a person receiving a social transfer who begins earning a small income. If crossing a particular income threshold causes the person to lose the entire benefit, the individual can face a perverse incentive: earning more may make them financially worse off. This is the poverty trap. It is fundamentally a mathematical problem. A welfare system should ideally create a smooth transition from dependence to independence. Benefits should decline gradually as income increases, rather than creating a cliff where a small increase in earnings results in a large loss of support. Economists have proposed mechanisms such as the negative income tax precisely because of this problem.

Count graduations, not enrolments

The objective should therefore not be to celebrate the number of people enrolled in social welfare. The better metric is how many people graduate from welfare into sustainable self-sufficiency. That is the difference between managing poverty and reducing poverty. A social protection system should not inadvertently make poverty a permanent economic category. It should provide a bridge through which people can move from vulnerability to productivity, income generation and independence.

So, should churches be taxed?

This brings us back to the provocative question about churches. Should churches in Zambia be taxed? Perhaps the better question is: what should qualify an institution for tax-exempt status? Religious organisations can provide enormous social value. Churches operate schools, clinics, orphanages, feeding programmes, scholarships and other community initiatives. In some communities, they provide services where government capacity is limited. That social contribution should be recognised. But recognition should also come with accountability.

If a religious institution receives significant tax privileges because it performs a public or charitable function, there should be a transparent mechanism for demonstrating that public benefit. I would therefore support a system where large religious organisations receiving substantial tax privileges are required to report, in a proportionate manner, on their community impact and social services. How much money was received? How much was spent on administration? How much went towards schools, clinics, scholarships, food programmes and community infrastructure? How many people benefited? This does not have to become an attack on religion. Quite the opposite. If churches are making a significant contribution to national welfare, measuring and publishing that contribution could strengthen the case for their preferential treatment.

Taxation is a design problem

The deeper issue is that taxation is often discussed purely as a government revenue problem. But taxation does much more than finance government. It influences investment decisions, employment, consumption, entrepreneurship and wealth distribution. A poorly designed tax can discourage productive activity. A poorly designed welfare system can discourage people from increasing their income. A poorly designed exemption can create opportunities for abuse. And a poorly designed social programme can measure success by the number of people dependent on it rather than the number of people who no longer need it. These are not merely political questions. They are economic design problems. And economic design is ultimately mathematics applied to human behaviour.

The lesson for Zambia

The lesson I take from the Torah is not that Zambia should copy an ancient tax code. The lesson is that taxation and social welfare should be built around explicit principles. Contribution should be related to capacity. The vulnerable should be protected. Redistribution should pursue justice rather than dependency. Tax exemptions should correspond to measurable public value. And economic incentives should matter.

Zambia has been independent for more than six decades. It is therefore reasonable to ask whether we should continue thinking of our tax system primarily as an inheritance from the colonial administration, or whether we are ready to develop a tax philosophy designed around the realities of the Zambian economy. We need not choose between economics and morality. Perhaps we need both.

The Torah provides one ancient framework for thinking about the relationship between wealth, taxation, poverty and social obligation. Modern economics provides another. The interesting question is what happens when we put the two into conversation. I explored some of these ideas in greater detail in my 2024 paper, Tzedaka: A Jewish Approach to Zambian Social Welfare, available on ResearchGate.

The point is not that the answer to Zambia’s economic problems is hidden in an ancient book. It is that sometimes an ancient question can force us to rethink a modern problem: what is the fair contribution of those who have more, and what obligation does society have to ensure that those who have less can eventually stand on their own?

Perhaps that is where the mathematical derivative of the Torah becomes relevant to the economics of Zambia.

Editor’s note: This article was originally authored by Kampamba Shula and published on the Katondo Street Journal. The original article can be found at katondostreet.com.

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