Dominance of Sogdian Merchants on the Silk Road During the Medieval Age: a Semi-private Ordering Organization,
Janet T. Landa (York University, Toronto, Canada)

Abstract : This paper describes the organization of a trade network along the Silk Road in the seventh and eighth centuries, a trade network dominated by an ethnically homogeneous Sogdian merchant group. I will apply my theory of the ethnically homogeneous middleman group (EHMG, Landa 1981) - involved in the marketing of smallholders' rubber in SouthEast Asia - to explain the success of the Sogdian merchants in the medieval period. A new twist in this paper is that unlike the Chinese EHMG, which is a private ordering organization, the Sogdian merchant group had some governmental participation, hence the Sogdian merchant group was a semi-private ordering phenomenon.

Assortative Matching in Risk-sharing Networks: Evidence from Thai Villages
Ju QIU (Governance Analytics, Paris Sciences & Lettres)

Abstract : We look into the formation of risk-sharing groups in social networks. In particular, we are interested in risk-sharing link formation among agents of different risk types. Previous empirical studies almost consistently find that informal mutual insurance links are largely formed based on homophily. In this study, we point out that the evidence of homophily, established in the previous literature, is not robust if we use panel data documenting people’s network connections instead of using snapshot self-reported social links, and if we introduce degree heterogeneity in the econometric model for testing. We retrieve networks in 16 Thai villages based on records of economic in- teractions over 84 months. Our results show negative assortative matching with respect to risk types in kinship networks, which is consistent to the pre- diction of a standard risk-sharing matching game. However, links beyond kinship tend to follow a positive assortative matching process, even though the tendency is trivial. We apply the model of risk sharing in social networks (Ambrus et al. (2014)) to further explore the mechanism of the pattern of sorting. Our theoretical deduction indicates that the benefit of risk diversification through informal risk-sharing increases with the aggregated social value of network connections in the risk-sharing network.

Governing the Trade in High Value Fine Art
Anja Shortland (King's College London)
Andrew Shortland (Cranfield University)

Abstract : Global art sales now exceed $60bn a year. In 2015, just over a quarter of this volume came from objects sold for more than $1mn at auction sales. With rising prices, art and cultural property crime has become a major criminal market. What underpins the trust of buyers in this market which is potentially riddled with “lemons”– i.e. fakes, forgeries and items with defective legal titles? Public funding to tackle art theft and fraud is very limited. We study the complex private governance system ordering this market. A multiplicity of experts screens high value objects for ownership and authenticity before each sale. Afterwards, there is a further layer of inspection. Generally, mistakes are resolved informally and confidentially. We show that the system is a polycentric governance system in which different actors govern distinct but overlapping issue areas, each of them working for individual profit (and prestige). The system is constantly challenged by changes in regulation or societal norms, litigation and criminal innovations. If private governance fails, entire sub-markets disappear until agents develop credible new solutions. We thus observe an evolving private governance regime rather than one in “steady state”.