SAN FRANCISCO — Something odd is going on in the pharmaceutical world: Though the industry is coping with a sluggish economy and bracing for federal cuts in medical research funding, the mood among the 8,000 executives at the industry’s premier investors conference is decidedly upbeat.

As the 31st annual J.P. Morgan Healthcare Conference got underway Monday, talk was about the pace of US drug approvals picking up after a relative dry spell. Last year, the Food and Drug Administration allowed 39 new treatments on the market, up from 30 in 2011 and the most in 16 years.