There's a simple explanation for this. Banks are able to offer employees attractive working conditions and fringe benefits, as well as flexible programs to help workers balance work and family life. Therefore, employees choose not to be represented by a union. Some have joined a union for two, three, four or five years, and then opted out. The right to join a union is a fundamental right of every employee.
On December 5th, 2006. See this statement in context.