This paper analyzes the evolution of the incidence and intensity of nontariff measures (NTMs). It extends earlier work by measuring protection from NTMs over time from a newly available database and provides evidence on the evolution of NTMs. In particular, building on Kee et al. (Econ J 119(534):172-199, 2009), this paper estimates the ad valorem equivalents of NTMs for 97 countries at the product level over the period 1997-2015. We show that the incidence and the intensity of NTMs were both increasing over this period, with NTMs becoming an even more dominant source of trade protection. We are also able to investigate the evolution of overall protection derived jointly from tariffs and NTMs. The results show that the overall protection level, for most countries and products, has not decreased despite the fall in tariffs associated with multilateral, regional and bilateral trade agreements in recent decades. We also document an increase in overall trade protection during the recent 2008 financial crisis. Overall, this study sheds light on an underresearched aspect of trade liberalization: the proliferation and increase of NTMs.

PurposeThe first purpose of this paper is to situate and conceptualise ambiguity in the operations management (OM) literature, as connected to supply chain decision-making (SCDM). The second purpose is to study the role of ambiguity-coping mechanisms in that context.Design/methodology/approachThis research uses the behavioural decision theory (BDT) to better embed ambiguity in a generic SCDM framework. The framework explicates both behavioural and non-behavioural antecedents of ambiguity and enables us to also ground the “coping” mechanisms as individual and organisational level strategies. Properties of the framework are illustrated through two “ambiguous” events – the 2011 Thai flood and Covid-19 pandemic.FindingsThree key findings are documented. First, ambiguity is shown to distinctively affect supply chain decisions and having correspondence with specific coping mechanisms. Second, the conceptual framework shows how individual coping mechanisms can undermine rational-based organisational coping mechanisms, leading to “sub-optimal” (poor) supply chain decisions. Third, this study highlights the positive role of visibility but surprisingly organisational “experiential” learning is imperfect, due to the focus on “similar” past experience and what is known.Originality/valueThe paper is novel in two ways. First, it introduces ambiguity – an often neglected concept in operations management – into the supply chain lexicon, by developing a typology of ambiguity. Second, ambiguity-coping mechanisms are also introduced as both individual and organisational strategies. This enables the study to draw distinctive theoretical and practical implications.

Chinese scientific output has increased dramatically in recent years, but its internal spatial structure has received scant attention. Estimated gravity models of intercity scientific coauthorships show that there are two types of spatial political bias in China, apart from the expected mass and distance effects. Intercity coauthorships involving Beijing are more common than Beijing's output volume and location would imply, and this Beijing bias is increasing over time. The second type o f spatial political bias is greater intraprovincial collaboration than is accounted for by size and distance. The geography o f Chinese science is thus not only monocentric as regards overall scientific output, but also exhibits unusually hierarchical collaboration patterns. Unlike in Europe and North America, national and regional capitals are becoming ever more important as scientific coordination centers.

Purpose -This paper provides quantitative evidence of natural disasters' effect on corporate performance and studies the mechanisms through which the supply chain moderates and mediates the link. Design/methodology/approach -Using two major natural disasters as quasiexperiment, namely the 2011 Japanese earthquake-tsunami (JET) and Thai flood (TF), and data over the period 2010Q1-2013Q4, effect of these events on end assemblers' performance is studied, with a focus on the personal computer (PC) supply chain. The moderating influence of delivery and sourcing -as supply chain flexibility and agility -are examined through end assemblers' and suppliers' inventory. The suppliers' mediating role is captured as disruption in obtaining PC components through their sales. Findings -Only JET had any negative effect, further quantified as short-term and long-term. The TF instead portrays an insignificant but positive aftermath, which is construed as showing learning from experience and adaptability following JET. Inventory matters, but differently for the two events, and suppliers only exhibit a moderating influence on the assemblers' disaster-performance link. Originality/value -Natural disasters, as catastrophic vulnerabilities, are distinct from other vulnerabilities in that they are hard to predict and have significant impact. Since little is known about the impact of natural disasters on firm performance and how supply chain mechanisms moderate or mediate their impact, they should be distinctly modelled and empirically studied from other vulnerabilities. This paper sheds light on supply chain resilience to such events with the role of dynamic capabilities.

Using new estimates of ad valorem equivalent of nontariff measures (NTMs) over time, this paper examines NTMs and tariffs’ relationship for a sample of 70 economies for 4,949 products at the 6‐digit harmonized system level over the period 2003–2015. A panel data methodology models the lagged adjustment of NTMs to tariffs, consistent with a causal relationship. Trade policy substitution is found when the models are estimated in both levels and changes; with this holding for both OECD and non‐OECD countries, but not for the agriculture sector in OECD countries. Overall, there is a fairly complete substitution between policy instruments in absolute terms.