Megan McArdle and Stuart Buck have an opinion piece in the Washington Examiner on the innumeracy, economic and otherwise, of many reporters:

…many conservative readers attributed the misleading figures to liberal media bias. But it is more likely ignorance than malice. Every year, scores of fledgling journalists pour out of liberal arts programs. Though many will need to pick through mountains of statistics in search of the truth, few have been taught the skills to do it.

They quickly become victims of advocacy groups pushing skewed statistics. Through ignorance, they may also start manufacturing their own flawed numbers. Since number-crunching beats (such as business and finance) are generally viewed as a tedious waystation en route to more interesting beats, few are enthusiastic about developing these skills. And their editors may not be in any position to help them.

The problem is compounded by the fact that journalists who do know how to read a balance sheet, run a regression, or analyze economic data, can generally get a job that pays a lot more than journalism. Some stay in the field out of love for their work (journalism is a really great job), but in our experience some of the best flee to greener pastures.