The exponent of the slope for the power-law line drawn in a bi-log plot of node frequency over degree distribution. Networks characterized by strong hierarchical configurations, such as scale-free networks (few large degree nodes and many small degree nodes), often have values over 1 or 2. A value lower than 1 indicates the absence of scale-free properties and a limited hierarchy among nodes. The above graph reveals a hierarchy of 1.338, which is fairly pronounced.