The Gulf Olmec of San Lorenzo, Veracruz, engage scholars focused on early sociopolitical complexity and interregional interaction. Although many Olmec “firsts” remain debated, from specific icons to the site's position as an urban center, authors Kenneth Hirth and Ann Cyphers provide compelling evidence for the presence at San Lorenzo of Mesoamerica's earliest specialized obsidian blade workshop. It is difficult to imagine two colleagues better suited to exploring Olmec lithic economy, because they bring decades of systematic research on ancient economies (Hirth) and intensive excavations at San Lorenzo (Cyphers). Hirth and Cyphers marshal an enormous and diverse database of 69,223 flaked stones that spans the site's millennium (1800–800 cal BC) of occupation, which peaked during the San Lorenzo B phase (SLB) from 1200 to 1000 BC. Wisely eschewing polemics on Olmec complexity, they establish San Lorenzo as a large capital covering 775 ha with a centralized political system governed by rulers and a nobility, supported by a network of lesser nobility at secondary centers. With a mean population of nearly 12,000, the site's SLB peak also coincides with the depletion of lacustrine resources and the reduction in availability of a key raw material—obsidian—that, intriguingly, was used almost exclusively in San Lorenzo's lithic economy.

The authors frame lithic economy as the procurement, production, distribution, and consumption of obsidian tools within and between domestic and institutional spheres. Their most substantive contributions encompass production, given their focus on the SLB obsidian pressure blade workshop at Puerto Malpica. This workshop was located advantageously at the southern tip of San Lorenzo Island for both riverine and overland transportation routes: it was a place through which all arrivals had to pass. Prior to and concurrent with this SLB workshop, most obsidian cutting tools were made on a household basis by percussion. The authors persuasively argue that pressure blades represent a specialized craft, with pre-SLB blades arriving as trade items, probably as part of the same networks as nodular obsidian cores destined for percussion.

With 30% of SLB flaked tools comprising pressure blades made by probable part-time specialists, the authors suggest that the loss of household economic independence was a response to obsidian shortages; pressure blade production more efficiently used obsidian than did percussion technology. Although the San Lorenzo elite supervised some types of craft production (such as basalt carving at the “Red Palace”), the authors propose an “independent crafting model” for obsidian pressure blade production: “entrepreneurial” artisans obtained raw material and distributed their products without elite involvement. In contrast to the traditional sequential removal of blades, which left a polyhedral core, the authors outline an alternative process employed at Malpica and previously unrecognized at Early Formative sites: the progressive production strategy, whereby the original blocky nodule was prepared to remove pressure blades early in the process, leaving half-cylindrical cores. The SLB scarcity of obsidian, however, precludes the discovery of such cores at Malpica because exhausted cores would have been further reduced using bipolar techniques. The authors usefully outline the full sequence and types of pressure blades that archaeologists can readily identify as evidence of the progressive production strategy.

To explore the procurement, distribution, and consumption of obsidian, the authors sourced a large sample of their temporally and spatially diverse dataset, including a variety of contexts from San Lorenzo's core, periphery, and hinterland sites. They document eleven obsidian sources used for percussion tools and ten for pressure blades during the SLB; the importance of distant sources such as El Chayal, Guatemala, and Ucareo, Michoacán, indicates that “resource provisioning was not structured purely in energetic terms” (p. 146). In contrast to the variety of sources evident in most SLB contexts, the Malpica crafters focused primarily (92%) on one (and most distant) obsidian source: Ucareo. The authors propose that obsidian nodules primarily moved through short relays in long networks of household-to-household exchange. With no local obsidian sources near San Lorenzo, such exchange mechanisms mitigate the distance between closer but still remote sources such as Paredón and the farthest source, Ucareo; thus, it was the ready availability of Ucareo obsidian in such networks, and not crafter preference, that led to its near-exclusive use at Malpica. To understand the movement of Ucareo obsidian, the authors rely primarily on pioneering 1970s literature from Oaxaca rather than more recently sourced obsidian databases from Oaxaca's highlands and coast.

Based on the reasonable assumption that Ucareo pressure blades consumed throughout spatially diverse SLB contexts represent Malpica products, the authors test five distribution models. Their data primarily support dendritic distribution, whereby obsidian artisans collaborated with traders within and outside their residential community in down-the-line exchange relationships. Archaeological heterogeneity between contexts reflected the nature of personal contacts, which in some cases involved direct procurement from the workshop's artisans. Based on service and labor fealty obligations to elites established in Conquest-era documents, they suggest that Ucareo blades may also have arrived as tribute to the Red Palace's elites. Ucareo obsidian, however, rarely comprised the majority of blades in any SLB context. Thus, finished blades from multiple sources and obsidian nodules for percussion continued to arrive at San Lorenzo through previously established networks, further supporting their model of economic plasticity with parallel but different contemporaneous forms of exchange. Indeed, there may also have been centralized resource pooling at the community level for specific obsidian sources.

Demonstrating the benefits of long-term interdisciplinary research, this book represents a model of clarity in writing and transparency in assumptions and epistemology. I particularly appreciated the authors’ candor on equifinality: they acknowledge when their impressive dataset cannot definitively support certain interpretations. While frequently invoking “efficiency” and “rational decision making,” the authors temper their formalist perspective by asserting that economic processes are socially mediated, with decision-making criteria “dictated by the values, mores, and economic constraints or incentives that are promoted or advocated within society” (p. 6). Based on Conquest-era accounts of Aztec craftsmen and markets, the authors cast the Malpica workshop's independent artisans as entrepreneurs and vendors who would have congregated to “sell their wares and services” (p. 163) at the nearby docks. They reject, however, the market as being a primary mechanism for SLB obsidian blade distribution, candidly noting it has only been “assumed” (p. 228) to be present in Late Formative Mesoamerica. A final highlight is the authors’ exploration of blade technology transmission through the lens of their independent crafting model; they may find it beneficial to incorporate community of practice perspectives in future analyses.

With high-quality illustrations and substantive data tables, this book represents a major achievement. It contributes to how we envision the San Lorenzo Olmec and how the study of ancient economies can inform analysis of larger social transformations. Each chapter stands on its own, facilitating the book's dissemination through assigned class readings and ensuring much-deserved greater exposure beyond Olmec and lithic specialists.