Research

Publications

14 works

Articles, chapters,
reports & thesis

Google Scholar ↗
Forthcoming

Living standards in Ghana, 1955–2005

I. Martins

Labour and Work in Ghana Since Independence · Edited by Gareth Austin, Akua Britwum, Lamine Doumbia, Andreas Eckert, and Nana Yaw Sapong. London: Bloomsbury Academic

Using consumption baskets matched to the diets of Ghana’s three ecological zones, I show that national baskets understate living standards in the northern savannah, and that the widening gap between regions in 1988–2005 came mainly from rural areas.

Forthcoming

Från arbetskraft till kapital: Slaveriets ekonomiska logik i globalt perspektiv

I. Martins and E. Green

Statsvetenskaplig tidskrift

Enslaved people could serve as collateral as early as classical Athens and Rome, and in nineteenth-century Brazil and the Cape Colony courts and foreclosure made slave-backed lending routine, so emancipation also wiped out collateral that creditors relied on.

2026

Capital and coercion: Slavery after the 1807 import ban in the Cape Colony

I. Martins

European Review of Economic History · heag012

After Britain banned slave imports in 1807, wealthier households in Stellenbosch and Graaff-Reinet kept accumulating enslaved people, holding them as capital assets in a colony where capital was scarce.

Replication package ↗
2026

Theoretical foundations of the economics of slavery: Enslaved people as capital investments in the Atlantic world

I. Martins and E. Green

Journal of Global History · 21(1), 22–40

Comparing the United States, Brazil and the Cape Colony, we show that enslavers held enslaved people as both labour and capital investment, and that this investment role is key to explaining why slavery persisted.

2025

Is the business of conquest the conquest of business?

I. Martins

The Case Centre · 225-0045-1

Students take the seats of the Heeren XVII, the VOC’s governing board, and decide where the company should expand next, weighing profit against the political and ethical costs of conquest.

2024

Fertility responses to short-term economic stress: Price volatility and wealth shocks in a pre-transitional settler colony

J. Cilliers, M. Mariotti, and I. Martins

Explorations in Economic History · 101620

Cape settler households that lost slave wealth at emancipation in 1834 appear to have postponed births, while price volatility had no clear effect on conceptions.

Replication package ↗
2024

Resilience to shrinking as a catch-up strategy: A comparison of Brazil and Indonesia, 1964–2019

T. Axelsson and I. Martins

Studies in Comparative International Development · 59(3), 491–516

We argue that differences in structural transformation, autonomy and inclusion explain why Indonesia has weathered economic shrinking better than Brazil since 1964.

2024

Inequality, poverty, and resilience to economic shrinking

A. Smythe, I. Martins, and M. Andersson

International Journal of Development Issues · 23(1), 40–81

Across 23 developing countries over 42 years, falling poverty is associated with fewer episodes of economic shrinking, while changes in income inequality show no such relationship.

2023

An age of disentangled research?

I. Martins and S. Schwaag Serger

Issues in Science and Technology · 40(1), 38–43

Coauthorship between Chinese and US researchers has begun to decline, and we ask what growing political constraints mean for international science.

2023

Legacies of loss: The health outcomes of slaveholder compensation in the British Cape Colony

I. Martins, J. Cilliers, and J. Fourie

Explorations in Economic History · 101506

Slaveholders who lost more wealth through the partial compensation of 1834 lived slightly shorter lives, an effect concentrated among older owners; their children and grandchildren were unaffected.

Replication package ↗
2023

Shifting patterns in international research cooperation

I. Martins and S. Schwaag Serger

STINT · Report

Chinese-based scholars now publish more than their US-based colleagues in nearly every science and medical field, and coauthorship between the two countries fell during the COVID-19 pandemic while collaboration with Latin America, Africa and Europe held steady.

2020

Collateral effect: Slavery and wealth in the Cape Colony

I. Martins

Lund University · PhD thesis

Without secure title to land or organised credit, Cape slaveholders used enslaved people as financial assets to raise capital, which helps explain how slavery worked and persisted in the colony.

2019

What caused poverty reduction in Brazil during the 2000s: Sectoral growth or public expenditures

A. Palacio and I. Martins

OASIS. Observatorio de Análisis de los Sistemas Internacionales · 31, 185–213

Growth in services, led by public administration, did more than agriculture to reduce poverty in Brazil in the 2000s, and state and municipal spending on human capital did more than federal cash transfers.

Under review

5 manuscripts

The case for artisanal doctoral supervision

I. Martins

Studies in Higher Education · Revise and resubmit

Universities track doctoral students through study plans and progress reviews. I propose revisable plans and brief records of reasons, so that supervisors remain accountable and students can still change course when new evidence calls for it.

Retrieval-restricted reasoning: Supporting scholarly synthesis with language models

I. Martins

Historical Methods: A Journal of Quantitative and Interdisciplinary History · Revise and resubmit

I built a method that lets language models write literature reviews only from sources the researcher supplies; across 100 test reviews with 4,767 citations, 99 contained none of the five measured citation errors.

Replication package ↗

Weather as a vector of inequality

I. Martins, S. Grab, and E. Green

Nature Communications · Revise and resubmit

Linking weather to 25,000 household tax records, we show that wealthier households more often owned the commodities that seasonal weather favoured, and years when weather raised returns to those commodities were years of wider inequality in movable assets.

Read preprint ↗ Replication package ↗

Slave emancipation and agricultural output in the Cape Colony

I. Martins

Cliometrica · Submitted

After emancipation, Stellenbosch farms whose compensation fell further short of their slaves’ assessed value lost more wine and grain output, especially large mixed producers, consistent with the loss of slave property used in lending.

Replication package ↗

Democracy and rural inequality in Kenya, 1997–2010

J. Makuei and I. Martins

African Affairs · Submitted

Across 31 Kenyan constituencies from 1997 to 2010, rural households gained better access to fertiliser, roads and markets after the first democratic transfer of power, while the gap in household wealth between constituencies barely changed.

Work in progress

7 manuscripts

Income inequality in late colonial Angola, 1940–1970

I. Martins

Wealth and adult mortality in a pre-industrial settler society: Evidence from Cape probate inventories

J. Cilliers and I. Martins

Held by the elite: Monopoly rights and family fortunes at the Cape of Good Hope, 1680–1794

I. Martins, J. Schoots, and E. Green

The Dutch East India Company auctioned the right to sell alcohol at the Cape every year. The settlers who won these rights already owned enslaved people more often than others, and those who ran them as a business accumulated more, while their families lasted no longer than other settler families.

Catch-up and resilience to shrinking, 1890–2019

A. Smythe and I. Martins

Across 105 countries since 1955, productivity and inputs often moved in opposite directions, and a country’s earlier record of growing and shrinking helps predict its later expansion.

Forebearers: The forgotten women of the Cape Colony

J. Cilliers and I. Martins

What are institutions made of? A social contract approach

I. Martins and E. Green

The Ghanaian divergence: Prices, incomes and living standards after independence

I. Martins, P. Aboagye, and G. Austin

Essays & media

11 contributions