Dean Spears and Michael Geruso’s After the Spike presents a bold, data-rich, and ethically provocative examination of what they believe to be humanity’s most underappreciated crisis: the quiet yet irreversible shift towards global depopulation. Structured as both a demographic revelation and a philosophical call, the book reads like a time capsule from a world at its numerical peak, urging readers to take seriously a future where fewer humans may mean fewer possibilities.
The authors begin not with panic but with precision: “In 2012, 146 million children were born. That was more than in any prior year. It was also more than in any year since.” This data point becomes the fulcrum of their narrative: the ‘spike’ in global births that marks a high point before a long, exponential decline. The graphic image reproduced in the book’s cover—a sharp spike rising after millennia of slow growth, then plunging—feels more like an epitaph than a chart.
Much of the book’s strength lies in its explicit rejection of the simplistic notion that fewer people automatically lead to a better world. Spears and Geruso carefully dismantle this assumption, acknowledging that many believe a smaller population means lower carbon emissions, reduced strain on resources, and greater sustainability. However, they argue that such views overlook a crucial point: people are the driving force behind human progress.
In the second part, they take up ‘the case against people,’ grappling with the hard questions. What if future children are born into an unjust world? What if they contribute to climate degradation? The authors don’t dismiss these concerns. Instead, they weigh them against the costs of inaction: ageing societies, innovation slowdowns, and even existential risks. Citing everything from vaccines to Beethoven, Spears and Geruso argue that progress—technological, cultural, moral—is born from the unpredictable brilliance of people.
India plays a central role in the book, not only as a statistical heavyweight but as a moral and empirical anchor in the authors’ case. Now the world’s most populous country, India has already reached below-replacement fertility—a shift that upends the long-standing narrative of overpopulation. What makes India especially significant is not just the decline in birth rates, but the remarkable convergence across regions, religions, castes, and education levels. The authors note that between 1992 and 2021, the fertility gap between high and low-fertility states, such as Uttar Pradesh and Tamil Nadu, narrowed substantially, and similar reductions are observed between social groups. India now stands in the demographic middle: middle-income, mid-life expectancy, and mid-level fertility, making its trajectory a bellwether for the planet. Its path suggests that global depopulation may no longer be confined to rich or Western nations, but a shared future is in the making.
One of the book’s most striking insights is its redefinition of reproductive choice—not as a personal cost but as a public investment. Parenting, they argue, is both labour and infrastructure. Like roads and power grids, the decisions of today’s parents shape tomorrow’s societies. Their critique of policy shortcomings—from ineffective financial incentives to unsupportive work environments—is grounded in evidence.
Still, Spears and Geruso are not traditional pronatalists as the book is careful to never prescribe parenthood: “It is not a solution to ask anyone to have more children than they want. It’s society’s collective task to lift the burdens of parents and other caretakers. Externalities need cooperative solutions.” This ethos sets them apart from demographic alarmists or coercive policymakers. Their goal is not to restore some mythical golden era of big families, but to foster the conditions in which people can choose freely, without the invisible hand of economic pressure or cultural anxiety.
What the book offers is not fearmongering, but foresight, and it challenges the prevailing idea that fewer people will mean fewer problems. Spears and Geruso write in a tone that is compassionate but unsentimental, pairing statistical clarity with moral urgency. Their narrative voice moves easily between field anecdotes from rural India and macroeconomic projections, and their language—precise, engaging, and often lyrical—makes even complex demographic arguments accessible. Like any work of deep scope, some chapters delve into population ethics with philosophical abstraction that may daunt casual readers. Their final chapters on policies to reverse depopulation are rich in critique but lean toward concrete proposals. One wishes for more examples of what aspiring bigger might look like in policy form.
In an era of planetary anxiety—characterised by climate change, automation, and pandemics—this book reminds us that the future may be shaped not just by the forces we fear, but also by the absences we overlook. After the Spike is not merely a demographic treatise; it is a manifesto for reinvesting in the human future.