AJAX is much slower in the production environment than in the development environment

I'm using Commerce AJAX in the shopping cart in Drupal 7, and the average time for an AJAX call on the development site is 100 to 200 ms. On the live site, these calls take 1-3 seconds. The development code base and the database are up-to-date with the production site.

Is this most likely a problem with the hosting environment?