or intensive margin in the traditional ‘dynamical’ way, i.e. by accounting for the variation of trade connections and/or their weights over time. On the contrary, it allows us to identify a bias towards either the extensive or the intensive direction in a novel, static fashion, by exploiting a mathematical property of the null model specifying both strengths and degrees. Moreover, the entity of the bias can be exactly quantified for each pair of countries, allowing different pairs of nodes to be characterized by opposite tendencies.

Our paper is organized as follows. In Sec. \[sec:data\] we introduce the trade data used and briefly summarize the methodology we employ to specify both strengths and degrees in weighted networks [@Squartini_Garlaschelli_2011; @mastrandrea2013enhanced]. In Sec. \[result\] we apply the methodology first to a reference year, then to several temporal snapshots, and finally to different aggregation levels (commodity classes) of the world trade multiplex. In Sec. \[sec:discussion\] we discuss some general economic implications of our results and their relation with the more traditional literature about intensive and extensive margins of trade.

Data and Methodology\[sec:data\]
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As we mentioned, our analysis builds upon previous studies of the WTW that showed that the degree sequence is able to 