def allocate_available_excess(region):
    """
    Allocate available excess capital (if any).

    """
    difference = region['total_mno_revenue'] - region['total_mno_cost']

    if difference > 0:
        region['available_cross_subsidy'] = difference
        region['deficit'] = 0
    else:
        region['available_cross_subsidy'] = 0
        region['deficit'] = abs(difference)

    return region