The economic package includes old commands that are now deprecated within LaTeX. This caused me a problem using the AER bibliography style (aer.bst), and likely causes problems with other BibTeX styles too. My particular problem was with scrartcl refusing to recognise the \bf command rather than the newer \textbf version.
Very specifically, the problem was “Class scrartcl Error: undefined old font command `\bf’.”
The fix for this is simple. Just include the following two lines in the preamble of your document.
\DeclareOldFontCommand{\bf}{\normalfontbfseries}{\textbf}
\DeclareOldFontCommand{\it}{\normalfont\itshape}{\textit}
You could alternatively open up your *.bst file and manually change the code, but the two lines above should fix it.