<p><strong>Be very careful fitting power laws!!</strong> Many reported power laws are actually badly fitted by a power law. See <a href="http://dx.doi.org/10.1137/070710111" rel="noreferrer">Clauset et al.</a> for all the details (also on <a href="http://arxiv.org/abs/0706.1062" rel="noreferrer">arxiv</a> if you don't have access to the journal). They have a <a href="http://tuvalu.santafe.edu/%7Eaaronc/powerlaws/" rel="noreferrer">companion website</a> to the article which now links to a Python implementation. Don't know if it uses Scipy because I used their R implementation when I last used it.</p>
Fitting a pareto distribution with (python) Scipy
<p>I have a data set that I know has a Pareto distribution.  Can someone point me to how to fit this data set in Scipy?  I got the below code to run but I have no idea what is being returned to me (a,b,c).  Also, after obtaining a,b,c, how do I calculate the variance using them?</p>

<pre><code>import scipy.stats as ss 
import scipy as sp

a,b,c=ss.pareto.fit(data)
</code></pre>