In JIRA, in order to be able to configure the options of a select list, checkbox or radio button custom field, a user must have "JIRA administrator" global permission.
This is true as well to set the default value for any custom field.
Until now, you would have only two options:

• the best practice is to grant "JIRA Administrator" permissions only to a few people, because that permission allows a user to change almost every JIRA configuration. However, any change to a custom field must pass through a central administration and in big organization this might take more than users would like, or
• you could give JIRA administration permissions to all your Project Managers, allowing them to edit field configurations as much as they like. But an unexperienced JIRA administrator might disrupt the instance or generate side effects: with great power comes great responsibility!
  The Configuration Delegation add-on for JIRA allows JIRA administrators to grant to project administrators the permission to edit only the configuration of some custom fields (options and default values), without giving away the precious superuser powers.
  Installation
  Configuration Delegation is available on the Atlassian Marketplace here. To install it, go to the Plugin Manager in JIRA administration section of your instance, search for "Configuration Delegation", then click "Install".
  If your JIRA instance cannot access the Atlassian Marketplace, download the plugin here, then upload it using the Plugin Manager of your JIRA instance.
  
  How to grant a Project Administrator permissions to edit a custom field configuration
  No configuration is required to make the plugin work! However, you might have to create a new context for your existing fileds in order to allow a Project Administrator to edit the configuration of a custom field.
  For example, if this is the configuration of a custom field:
  
• if a user has the Administer Project permission for both "Project A" and "Project B", he will be able to edit the "Project A & B" context;
• if a user has the Administer Project permission only for either "Project A" or "Project B" he won't be able to edit the context. This is to grant that the actions of a Project administrator don't have side effects on projects he cannt administer.
  How a Project Administrator can edit a custom field configuration
  In the Project administration tab, the plugin adds a new link: Configure Custom Fields
  
  
  Click on the link "Configure" to edit the default value or the custom field option.
  The following field types are supported:
• all JIRA standard custom fields (text, number, select list, radio button, checkbox…);
• multi level cascading select list.
  SUPPORT SITE
  We support Configuration Delegation. You can visit the support site to get help.