Some hiring managers use certifications to filter resumes. I specifically caution against that practice in the book. I'm not a fan of certifications. Michael Schrage's column Hiding Behind Certification is another article about why certifications are not a good predictor of job success. Here are two quotes I particularly liked:
“The truth — as we all so bitterly know — is that the IT world is filled with certified, credentialed and accredited idiots.”“…the real value of credentials and certifications like CMMs and MBAs is not that they indicate greater skill, but they signal to the market that these individuals and organizations will jump through hoops to demonstrate how much they care about being seen as top-notch. … the willingness to procure credentials can reveal more about attitude than aptitude.
Although Schrage is talking about IT, his observations aren't limited to IT. Unless you're talking about licenses which require some sort of an apprenticeship, certifications are no way to screen resumes or make a hiring decision.