Instead of finding a way to get static variables working, I prefer to simply create a getter function. Also helpful if you need arrays belonging to a specific class, and a lot simpler to implement.
class MyClass{ public static function getTypeList() { return array("type_a"=>"Type A","type_b"=>"Type B", //... etc. ); }}Wherever you need the list, simply call the getter method. For example:
if (array_key_exists($type, MyClass::getTypeList()) { // do something important...}