Custom post type capability type ‘page’ not working

I’ve taken this from another site I have made which uses the hierarchical structure and it works. (I have amended to fit your post type)

function register_publications_cpt() {

        $labels = array(
            'name' => _x('Publications', 'post type general name'),
            'singular_name' => _x('Publication', 'post type singular name'),
            'add_new' => _x('Add New', ''),
            'add_new_item' => __('Add New Publication'),
            'edit_item' => __('Edit Publication'),
            'new_item' => __('New Publication'),
            'all_items' => __('All Publication'),
            'view_item' => __('View Publication'),
            'search_items' => __('Search Publications'),
            'not_found' =>  __('No Publications found'),
            'not_found_in_trash' => __('No Publications found in Trash'), 
            'parent_item_colon' => '',
            'menu_name' => 'Publications'
        );

        $args = array(
            'hierarchical' => true,     
            'labels' => $labels,
            'public' => true,
            'publicly_queryable' => true,
            'show_ui' => true, 
            'show_in_menu' => true, 
            'query_var' => true,
            'rewrite' => true,
            'capability_type' => 'page',
            'has_archive' => false, 
            'menu_position' => 22,
            'supports' => array( 'title', 'editor', 'author', 'thumbnail', 'revisions', 'page-attributes', 'custom-fields' )
        ); 

        register_post_type('publication', $args);

}
add_action('init', 'register_publications_cpt');