Old Developments

Kevin Lewis

January 20, 2024

Institutions, Trade, and Growth: The Ancient Greek Case of Proxenia
Pier Paolo Creanza
Journal of Economic History, forthcoming


Recent scholarship contends that ancient Mediterranean economies grew intensively. An explanation is that Smithian growth was spurred by reductions in transaction costs and increased trade flows. This paper argues that an ancient Greek institution, proxenia, was among the key innovations that allowed such growth in the period 500–0 BCE. Proxenia entailed a Greek city-state declaring a foreigner to be its “public friend,” a status that conferred both duties and privileges. The functions performed by “public friends” could facilitate economic transactions between communities. Accordingly, network and regression analyses establish a strong relationship between proxenia grants and trade intensity.

The oxygen bottleneck for technospheres
Amedeo Balbi & Adam Frank
Nature Astronomy, January 2024, Pages 39-43 


As oxygen is essential for respiration and metabolism for multicellular organisms on Earth, its presence may be crucial for the development of a complex biosphere on other planets. And because life itself, through photosynthesis, contributed to creating our oxygen-rich atmosphere, oxygen has long been considered as a possible biosignature. Here we consider the relationship between atmospheric oxygen and the development of technology. We argue that only planets with substantial oxygen partial pressure (pO2) will be capable of developing advanced technospheres and hence technosignatures that we can detect. But open-air combustion (needed, for example, for metallurgy), is possible only in Earth-like atmospheres when pO2 ≥ 18%. This limit is higher than the one needed to sustain a complex biosphere and multicellular organisms. We further review other possible planetary atmospheric compositions and conclude that oxygen is the most likely candidate for the evolution of technological species. Thus, the presence of pO2 ≥ 18% in exoplanet atmospheres may represent a contextual prior required for the planning and interpretation of technosignature searches.

Old World Trade Diasporas
Lisa Blaydes & Christopher Paik
Sociological Science, January 2024 


What explains worldwide, historical patterns of trade diaspora dispersal? In the premodern period, trade diasporas were among the most important communities facilitating cross-cultural exchange over long distances. We argue that two general principles explain the proliferation of premodern trade diasporas. First, diaspora merchants were drawn to wealthy societies with the goal of obtaining access to high-value luxury goods produced through the development of complex supply chains. Second, traders sought to establish diaspora communities in locations that exhibited bioclimatic complementarities to the merchant’s home region, thereby assisting the procurement of relatively uncommon natural resources. To empirically assess these arguments, we examine the historical record for information about the product composition of historical trade; collect data on the locations of trade diaspora communities across Eurasia between 600 and 1600 AD; and develop an agent-based model that specifies the agents’ (i.e., traders’) rule-based decisions to migrate in a wealth and resource-differentiated geographic space that represents Eurasia. Taken together, our findings describe the conditions that facilitated diaspora creation and historical cross-cultural exchange -- a topic of rich exploration in the fields of global historical sociology and international political economy.

The ramparts of Khaybar. Multiproxy investigation for reconstructing a Bronze Age walled oasis in Northwest Arabia
Guillaume Charloux et al.
Journal of Archaeological Science: Reports, February 2024 


The multidisciplinary investigation carried out between 2020 and 2023 by the Khaybar Longue Durée Archaeological Project (CNRS-RCU-AFALULA) demonstrates that the Khaybar Oasis was entirely enclosed by a rampart in pre-Islamic times, like several other large regional walled oases in north-western Arabia (Tayma, Qurayyah, Hait, etc.). The cross-referencing of survey and remote sensing data, architectural examinations and the dating of stratified contexts have revealed a rampart initially some 14.5 km long, generally between 1.70 m and 2.40 m thick, reinforced by 180 bastions. Preserved today over just under half of the original route (41 %, 5.9 km and 74 bastions), this rampart dates back to the Bronze Age, between 2250 and 1950 BCE, and had never been detected before due to the profound reworking of the local desert landscape over time. This crucial discovery confirms the rise of a walled oasis complex in northern Arabia during the Bronze Age, a trend that proved to be central to the creation of indigenous social and political complexity.

An archaeomagnetic study of the Ishtar Gate, Babylon
Anita Di Chiara et al.
PLoS ONE, January 2024 


Data from the marriage of paleomagnetism and archaeology (archaeomagnetism) are the backbone of attempts to create geomagnetic field models for ancient times. Paleointensity experimental design has been the focus of intensive efforts and the requirements and shortcomings are increasingly well understood. Some archaeological materials have excellent age control from inscriptions, which can be tied to a given decade or even a specific year in some cases. In this study, we analyzed fired mud bricks used for the construction of the Ishtar Gate, the entrance complex to the ancient city of Babylon in Southern Mesopotamia. We were able to extract reliable intensity data from all three phases of the gate, the earliest of which includes bricks inscribed with the name of King Nebuchadnezzar II (605 to 562 BCE). These results (1) add high quality intensity data to a region relatively unexplored so far (Southern Mesopotamia), (2) contribute to a better understanding of paleosecular variation in this region, and the development of an archaeomagnetic dating reference for one of the key regions in the history of human civilizations; (3) demonstrate the potential of inscribed bricks (glazed and unglazed), a common material in ancient Mesopotamia, to archaeomagnetic studies; and (4) suggest that the gate complex was constructed some time after the Babylonian conquest of Jerusalem, and that there were no substantial chronological gaps in the construction of each consecutive phase. The best fit of our data (averaging 136±2.1 ZAm2) with those of the reference curve (the Levantine Archaeomagnetic Curve) is 569 BCE.


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