China is famous for its population crises, but few in the population studies field will be aware of this one brewing in the nation's hospitals for high-tech fertility treatment. It is a crisis of infertility, in which some 10 percent of couples of childbearing age are unable to conceive naturally, largely, it is believed, because of male-factor infertility. And it is a crisis of sperm, in which sperm have declined both in quality—due most likely to the toxic effects of environmental pollution and the adoption of modern lifestyles and diets—and in quantity, as efforts to mobilize potential donors have failed to keep up with the insatiable demand. Fifty years ago, China had too many babies. Today, a perfect storm of ultra-low, later-in-life childbearing, appalling environmental pollution, and unhealthy lifestyles has left it with far too few, with all the angst that brings to infertile couples and economic planners alike. I know what to expect as I approach 84 Xiangya Road where the 15-story CITIC-Xiangya Reproductive and Genetic Hospital lies, home to one of the world's largest sperm banks and fertility clinics. Even so, I'm astounded. Hordes of people are milling around the entrance… Most of them are there to seek fertility treatment, clutching their queuing tickets as they wait their turn to be called to the triage desk that manages inquiries from new patients. I squeeze my way through the crowds outside and enter the hospital lobby. The cacophony is thunderous. Patients are impatiently asking when their turn might come while white-coated doctors and pink-coated nurses somehow go about their daily routines… Two men are wheeling a large tank of liquid nitrogen toward the elevator, pleading for headway as they inch forward… (pp. 2–3, describing the author's first day of fieldwork in 2011 in Changsha, Hunan Province). Wahlberg places sperm banking and artificial insemination by donor (AID) at the heart of China's twenty-first century efforts to produce that low-quantity, high-quality “optimal population” it has tried so hard to create since it launched the one-child policy four decades ago. As he shows, over the last few decades, sperm banking has gone from being a pioneering technology with an uncertain future, to being a major and mundane part of reproduction in the People's Republic of China. Today, China has 23 sperm banks, including some of the largest in the world. Though the first test-tube baby was born in 1983, it is only since 2003, when national legislation was passed legalizing and regulating the provision of assisted reproductive technologies (ARTs), that sperm banking and AID have become routinized reproductive practices. Just as an earlier generation of China population specialists emphasized the fundamental differences between China's state birth planning program and the more familiar Western-style liberal family planning programs, Wahlberg stresses the China-specific nature of the nation's sperm banking efforts. Unlike the more privatized and commercialized sperm banking projects found in many parts of the world, he argues, in China, sperm banking is part of a vast, state-managed, highly restrictive population/reproductive complex whose aim is to optimize the quantity and quality (as well as the distribution) of the nation's population. Though nothing about this was inevitable, Wahlberg's in-depth research reveals how virtually everything about China's experience with sperm banking—its historical development, its legalization, its workings, its still disappointing results—reflects the dynamics of the larger complex. And because of the overriding political importance of the population project, which remains a “basic state policy” (jiben guoce), sperm banking, Wahlberg argues, should be understood as yet another form of birth control, along with tubal ligation and all the rest. These are striking arguments that deserve our closest attention. First, some conceptual and methodological grounding. Many anthropological studies of sperm banking in the global South center on globalization and the problems that arise from importing Western technologies into technologically underdeveloped settings. In the China case, Wahlberg submits, more insight can be gained by focusing instead on questions of making and routinization—that is, how a particular style of sperm banking (with its distinctive logics, technologies, forms of personhood, regulations, and so forth) came to be established in a particular locale and made commonplace. Instead of the standard ethnography of the lived experiences of donors and recipients, Wahlberg offers an ethnography of China's sperm-bank “assemblage,” an in-depth, site-specific study of the ways particular juridical, medical, social, cultural, economic, and institutional configurations came to be consolidated over time in urban China. After eight years (2007–2014) of short-term or episodic fieldwork in Changsha and three other cities (as well as in his home country of Denmark), Wahlberg has put together a robust dataset that allowed him to piece together a picture of the routes by which sperm banking was routinized. The data include field notes on his observations in donor areas and sperm-processing laboratories of the sperm banks, and in the locales targeted by mobile sperm bank crews; interview notes from discussions with the pioneers of ART in China, numerous staff of sperm banks and fertility clinics, over 50 sperm donors, and 10 involuntarily childless couples; a hand-curated collection of scientific articles and reports, as well as field notes from a series of pathbreaking conferences and workshops on the ethics of sperm banking; a set of key legal documents on sperm banking; an array of flyers used to recruit donors; and, finally, an archive of news items and media stories on sperm banking in China. Drawing on these varied and engaging materials, Good Quality seeks both to describe and to account for the unique style of sperm banking found in China today. Much of that uniqueness stems from the political necessity that the field's founders faced of making their work on sperm banking fit the imperatives of the state's population project. Since the 1990s, the focus of China's population optimization efforts has shifted decisively from lowering quantity to raising quality, and here is where sperm banking and management have become so important. In the China context, sperm banks were allowed to exist only if they met the state's demands to foster the nation's quality by improving population genetics, preventing the transmission of both serious hereditary disease and bodily malformation. So overarching was the population-quality goal to China's sperm banks that Wahlberg often thought of his research as an effort to “follow the concept of ‘quality’ around as it circulated in different forms—as imaginary, technical specification, interpellation form [that is, a form that establishes particular identities, such as sperm donor], regulatory requirement, or marker of vitality” (p. 25). Assuring quality—of the donors, of the sperm, of the population, of the greater Chinese nation—is a major aim of actors at each stage of donor recruitment, sperm collection, and sperm processing, making this perhaps the central narrative thread in the text. At the donor-recruitment stage, for example, recruiters use the college entrance exam as a screening instrument to select “quality young men,” and then subject the potential donors to a battery of tests (for general health, disability, and genetic quality), applying such high standards that only between 15 and 30 percent of those screened end up qualifying to give their sperm “for the benefit of the childless and the glory of the nation.” In a China-specific rule, a limit of five pregnancies per donor is imposed in an effort to limit the impact of inbreeding (or consanguineous marriage) on the quality of the Chinese people. Once the sperm are collected, lab technologists subject them to techniques of assurance—routinized, quantified screening and quality-control practices that assure the viability, vigor, and purity of the banked “technosperm.” Because the “daily grind” activities in the lab are aimed at preventing the transmission of genetic and infectious diseases while promoting the transmission of valued traits (by methodically selecting quality donors), the sperm banks, Wahlberg argues, function as veritable state-sanctioned guarantors of quality sperm for the Chinese nation. The book's final chapter takes us very briefly into the world of infertile couples to track the process by which they “borrow sperm,” and reason about third-party conception. The interest shifts from assuring sperm quality to preserving the secrecy of the process. In a fascinating series of individual vignettes, Wahlberg shows how the profound stigmatization of male infertility in China, coupled with the fear of third-party-created children later disrupting family harmony, encourages everyone involved to engage in strategies of utmost secrecy—what Wahlberg dubs “trouble (or gossip) avoidance”—to make sure nothing that transpires in the clinic gets out. The author writes in lucid prose guided by a sure hand, and fills his chapters with fascinating, if sometimes dismaying, observations. In his remarkable chapter on “exposed biologies,” for example, Wahlberg weaves his way through the unsettled epidemiological debates about the causes of apparently rising infertility. The leading explanations include not only developmental sex disorders linked to exposure to industrial chemicals and the spread of distinctly unhealthy modern lifestyles, but also—in the case of female infertility—the iatrogenic effects of reliance on repeat abortion for premarital birth control (state-provided contraceptive services were restricted to married couples). Wahlberg has inadvertently uncovered yet one more grisly, unintended cost of China's state-driven fertility decline. Beyond his book's explicit goal of accounting for the unusual style of China's sperm banking efforts—what the author coyly calls “one-child assisted reproductive technologies (ARTs)” (p. 31)—Wahlberg makes a number of important contributions. Perhaps the biggest is to expand what counts as “population” to include ARTs such as AID. In placing ARTs firmly within the field of scholarly vision, he expands the scope of population sciences beyond demography to include reproductive sciences, such as genetics and endocrinology, and broadens the analytic framings of research to embrace STS notions such as assemblage and routinization. The collection of research methods grows accordingly. For China, Wahlberg's work decisively shifts the focus from quantity to quality. In recent years, and especially since the ending of the one-child policy, so much attention has been paid to the quantity question that the issue of quality has gotten short shrift. With his engaging ethnography and often heart-rending stories, Wahlberg reminds us that that is where much of the action is today. Following some other recent works, Good Quality also brings men more clearly into the picture as reproductive actors, as well as sufferers for the collective demographic good. In China, women have long borne the costs of the nation's state-managed reproductive modernization; in this case, Wahlberg shows, men are being asked to contribute as well, both as donors and as solvers of their families’ problems of involuntary childlessness. As in any study, and especially studies of understudied topics, there are a few gaps. Perhaps because of the difficulties of finding or interviewing involuntarily childless couples, the chapter on infertile couples undergoing donor-sperm insemination felt too short and too thin. As this was the final, so-what? did-it-work? chapter in the book, it should have provided answers, even if provisional, to some of the big questions about the real-world effectiveness of the sperm banking project. The author brings China's reproductive laws and regulations into the analysis—a rare and valuable contribution—yet he tends to treat them as unproblematic rules of the game, neglecting the complex politics by which such rules may or may not be carried out. Similarly, the author mentions the existence of a shadow economy of sperm—but treats it anecdotally. Readers will be keen to know it operated and how it was connected to, and undoubtedly shaped, the official system of sperm collection, freezing, and utilization. The story of the official system might look rather different had the unofficial system also been part of the account. Clearly, though, one cannot do everything in one short book. These are minor quibbles about a text that is a remarkable achievement by any measure. Good Quality offers fresh and engaging data, and a novel analytic approach and set of arguments about a rarely studied subject. The author's ideas are delivered in clear, lively prose infused with a sly sense of humor and deep empathy for his subjects. Good Quality represents, in short, some of the best that anthropology can offer to the more mainstream fields of population study. It is highly recommended for research and graduate and undergraduate teaching alike.