traded commodities).

It is important to realize the origin of the disagreement between the WCM and the real network. We note that the expected values under the WCM are similar to those predicted for a fully connected topology. Indeed, for a complete network we have $$\begin{aligned}
\langle k_i\rangle &=& N-1 \label{1} \\
\langle k^{nn}_i \rangle &=& N-1 \label{2} \\
\langle c \rangle &=& 1 \label{3} \\
\langle s^{nn}_i \rangle & =& \frac{\sum_i s_i}{N-1} = \frac{2W_{TOT}}{N-1} 
\label{4}\end{aligned}$$ where $N$ stands for the number of nodes in the network, while $W_{TOT}$ is the total weight of all edges. The above predictions can be confirmed in fig. \[AggBUN\]. So, the main reason why the WCM fails is the fact that it generates unrealistically dense (and sometimes almost fully connected) networks [@Squartini_etal_2011b_pre; @mastrandrea2013enhanced]. We also note that, despite the apparent good agreement between the observed weighted clustering coefficient and its expected value under the WCM (fig. \[AggBUN\]), one can show that the empirical total level of clustering is in general higher than the one predicted by WCM, both throughout the temporal evolution of the system and across its commodity-specific layers [@Squartini_etal_2011b_pre].

We note that another study [@fronczak2012statistical] also applied a variant of the WCM 