Jenny Trinitapoli An Epidemic of Uncertainty: Navigating HIV and Young Adulthood in Malawi University of Chicago Press, 2023, 288 p., $30.00.

An Epidemic of Uncertainty is a multicourse gourmet meal for demographers. It is a book to settle into, chew on, and ruminate over with good friends. Empirically dense, theoretically rich, and analytically smart, the book moves the reader effortlessly between sophisticated quantitative analyses and everyday village and town life in and around Balaka, Malawi. And it brings demography, in all its interdisciplinary and conceptual splendor, to bear on the new subfield, Jenny Trinitapoli, the book's author, wants to usher in: Uncertainty Demography. The book examines how a generation of Malawian youth, who have lived their entire lives under the shadow of a severe HIV and AIDS epidemic, are transitioning to adulthood and navigating the stuff of life—beginning and ending relationships, having children, and for some, getting and living with HIV, and dying—from AIDS or giving birth or lightning strikes, among other causes of death.

The book is based on an extraordinary and groundbreaking dataset, Tsologo La Thanzi (TLT: Healthy Futures in Chichewa), codesigned and led by Trinitapoli and her close collaborator Sara Yeatman. The impetus for the study was the observation that in Malawi, as in several other African countries, first sex, first marriage, and first birth unfold over a two-year period. Yet most major African surveys, most notably the Demographic and Health Surveys, collect cross-sectional data every five years, limiting analyses of the transition to adulthood. TLT (https://tsogololathanzi.uchicago.edu/, which is publicly available) is a longitudinal survey following respondents—young women and their male partners—over a 10-year period, from ages 15–25 to ages 25–35. The core survey included eight waves of data collected between 2009 and 2011, with each wave collected every four months. There was some attrition from the original sample—1505 respondents in 2009, to 1200 respondents in 2015 (80 percent of the original sample) to 1022 respondents in 2019 (68 percent) (p. 51). This led to a refresher sample collection in 2012 and 2019. Finally, there was follow-up data collection in 2015 and 2019. The survey, described in Chapter 2, is not just exceptional in its intensity but also in its creativity and methodological ambition. Data collection methods ranged from a standard survey questionnaire to biomarker data collection involving pregnancy and HIV testing, to card sorts, cognition tests, relationship scripts, literacy tests, vignettes, personal fieldnotes, first- and second-hand ethnographic observations, and a primary method for measuring uncertainty—bean counts. (Respondents could place up to 10 beans corresponding to their assessment of the probability of different event occurrences).

At the heart of the book is the argument that individual uncertainty, and how people make sense of it, has consequences for their subsequent actions, and further that individual uncertainty aggregates and works as a powerful social force and a major driver of demographic change at a population level. The case of Balaka is instructive: the HIV epidemic unfolded in a context with a plethora of other major and more immediate life uncertainties around livelihood, food insecurity, and morbidity and mortality from other causes. Taking uncertainty as a starting point, Trinitapoli turns standard “don't know” responses to survey questions on their head, showing how not knowing can drive population-level outcomes. She demonstrates this through measuring uncertainty and then examining responses and outcomes in subsequent surveys. Perhaps the biggest claim in the book is that uncertainty can be a more important driver of social action than certainty. For Malawian youth, the book convincingly shows, it accelerates life course transitions—into marriage, divorce, and parenthood—powering a “relationship churning” that puts them at risk of HIV acquisition and transmission as they move through the marriage regime. The book is convincing in making the case that not understanding uncertainty about a phenomenon of interest—the “don't knows” or the “known unknowns”—can lead to misunderstanding the phenomenon of interest, and missing the consequential ways it is shaping individual and population-level dynamics.

In the case of HIV uncertainty, described in Chapters 4 and 5, for example, Trinitapoli finds that nearly 40 percent of young people in the study are uncertain about their HIV status. Further, over the life of the study, she found not only that people move in and out of periods of uncertainty (as opposed to a permanent “worrier class,” p. 103), but that fully half the sample had experienced “acute uncertainty” (defined as —four to six beans, on a 1–10 scale), at different points in time, despite a 14 percent HIV prevalence in Balaka. In other words, the HIV uncertainty epidemic was bigger than the HIV epidemic. Trinitapoli found no effect of access to very frequent testing (every four months over more than two years for a sample of participants) on population-level uncertainty. Ironically, only testing positive led to HIV-related certainty. HIV uncertainty was also demographically consequential. Following the participants over time, she found it led to accelerated childbearing, and that increasing uncertainty was associated with significantly worse self-rated health, more sick days, and more depression. Indeed she concludes, HIV uncertainty, not just positivity, is “a clinically relevant condition”(p. 221).

HIV uncertainty arose from relationship uncertainty, examined in Chapters 6 and 7. Balaka features universal marriage (95 percent of young women married at least once over the study period), and almost 40 percent were divorced and/or remarried one or more times (pp. 138–139). Each relationship transition carried increased HIV risk—from 2012 on, over 20 percent of divorced and remarried women were living with HIV, more than twice that of women in their first marriage (p. 141). Relationship churning was driven by a high level of mistrust, suspicion, and anxiety around their partner's fidelity. And this was amplified by the fear of HIV acquisition and widespread cell phone use—users were more suspicious of their partners than nonusers. In Chapter 8, Trinitapoli then considers the larger “mortality landscape,” placing HIV/AIDS into context. The chapter examines the interaction between large-scale mortality declines in infant and adult mortality, and everyday perceptions of death, the so-called “drumbeat of funerals” at the individual, family, and village level. Almost half (44 percent) of the TLT sample had lost a sibling by 2019, and throughout the study period, participants attended at least one funeral a month. In the 2019 survey round, 40 percent attended two or more funerals a month (p. 190). Thus, despite population-level mortality declines, in daily life, mortality remained a major source of uncertainty for young people.

In this and other chapters, the book makes an important case for taking seriously “population chatter” or the significance of on the ground perceptions of demographic events; by weaving back and forth between accounts of everyday episodes and survey findings, it shows how consequential they are for young people's life course transition decisions and trajectories. Much of the population chatter in the book came from ethnographic observations written by “Gertrude.” We know that she is Malawian, an “extraordinary research assistant,” and that she has a good memory, but we are also told that “Gertrude's private life is not on display here” (p. 45). There is an ethical dimension here, which is well taken, but the reader is also left with several questions. What culture or social class did she come from? For example, I was surprised that she did not already know that she needed to carry a wrap just in case she had to cover herself for a funeral (p. 192)—was this practice unique to this ethnic group, was mortality lower where she came from? What did she find familiar or strange about Balaka? What did villagers think she was there to do? And how did she decide what to write about each day? Knowing this would help readers better understand the eyes through which they are viewing and coming to understand Balaka. More broadly, readers might wonder, how were the fieldnotes analyzed? What was the analytic process used to masterfully weave the various data components into the book? A methodological supplement engaging some of these questions would have further enriched this book's contribution.

Readers interested in pursuing uncertainty demography will be helped by Chapter 3, which engages in a rich, though largely uncritical, literature review of previous demographic work on uncertainty and offers a working definition of the phenomenon and subfield. The chapter is less clear, however, on where the frontiers of this field are, how this project in particular is located within that literature, and what questions or gaps are left for future demographers to take up. This book will surely launch a thousand ships. I hope Trinitapoli plans a companion article as a guide for others.

Finally, the policy implications of the book are immense. In Chapter 9, the book discusses ending problematic programs like conditional cash transfers to incentivize hospital births, better tests to eliminate the uncertainty period after HIV testing, doing more to end livelihood uncertainty, and “taming the mortality landscape” (p. 222) in order to reduce uncertainty in people's lives. However, if we take the book's arguments seriously—that relationship uncertainty underlies HIV uncertainty; that in fact there can be an “epidemic of uncertainty”; and that population-level changes, such as mortality reduction, do not necessarily filter down to population chatter or individual perceptions in a way that can translate to certainty—how then do we “treat” and create policy around uncertainty?

Overall, An Epidemic of Uncertainty is a tour de force. Its originality, sophistication, creativity, and the groundbreaking nature of the survey on which it was based, make this book an outstanding achievement. I anticipate it becoming a classic on graduate student syllabi and taking up permanent residence on demographers’ bookshelves.