def calculate_benefit_cost_ratio(region, country_parameters):
    """
    Calculate the benefit cost ratio.

    """
    cost = (
        region['network_cost'] +
        region['spectrum_cost'] +
        region['tax'] +
        region['profit_margin']
    )

    revenue = region['total_revenue']

    if revenue > 0 and cost > 0:
        bcr = revenue / cost
    else:
        bcr = 0

    return bcr