# Errata

I collect here a few mistakes, typically typos in mathematical expressions, that I found in my published papers. Please notify me if in that papers you notice something wrong which is not included here.

## Innovation and corporate growth in the evolution of the drug industry

• Authors: G. Bottazzi, G. Dosi, M. Lippi, F. Pammolli, M. Riccaboni
• Journal: International Journal of Industrial Organization
• Date: 2001

Page 1179, Equation 9: in the denominator the expression $$N-1$$ should be replaced with $$N$$ to read $p_{B.E.}(k) = \frac{ F+N-k-2 \choose N-k }{F+N-1 \choose N }$

## A New Class of Asymmetric Exponential Power Densities with Applications to Economics and Finance

• Authors: G. Bottazzi and A. Secchi
• Journal: Industrial and Corporate Change, 20(4), pp. 991-1030, 2011
• Date: July 4, 2011

In Section 2 of this paper something went really bad editing-wise.

Equation 5: the argument of the incomplete Gamma function is wrong. Equation 5 should read $F_{AEP}(x;\mathbf{p}) = \frac {a_l \, A_0(b_l)}{C} \; Q(\frac{1}{b_l},\frac{1}{b_l} \, \left|\frac{x-m}{a_l}\right|^{b_l}) \, \theta(m-x) + \left( 1- \frac{a_r \, A_0(b_r)}{C} Q(\frac{1}{b_r},\frac{1}{b_r} \, \left|\frac{x-m}{a_r}\right|^{b_r}) \right) \, \theta(x-m)$

Equation 6: the expression for the mean is correct. The expression for the variance should read instead $\sigma^2_{AEP} = \frac{a_r^3}{C}\, A_2(b_r)+\frac{a_l^3}{C}\, A_2(b_l) - \frac{1}{C^2} \left( a_r^2\,A_1(b_r) - a_l^2\,A_1(b_l) \right)^2$

Equation 7: there are several mistakes. The correct formula should read $M_h = \sum_{q=0}^h \, {h \choose q} \frac{1}{C^{h-q+1}} \left( a_r^{q+1} \, A_q(b_r) + (-1)^q a_l^{q+1}\, A_q(b_l) \right) \, \left( a_l^2\,A_1(b_l) - a_r^2 \,A_1(b_r) \right)^{h-q}$

## Cities and Clusters: Economy-Wide and Sector-Specific Effects in Corporate Location

• Authors: G. Bottazzi and U. Gragnolati
• Journal: Regional Studies
• Date: 30 Nov 2012
Page 10, Equation 12: the subscript "c" of the log function is in fact the name of the function of which the log is computed. The expression should start $\log c (\beta, x_l ) = \beta_1 \log POPULATION \ldots$