def CFE_mu(theta, l_tilde, n):
    """
    Marginal disutility of labor supply from the constant Frisch
    elasticity utility function

    Args:
        theta (scalar):  inverse of the Frisch elasticity of labor supply
        l_tilde (scalar): maximum amount of labor supply
        n (array_like): labor supply amount

    Returns:
        mu (array_like): marginal disutility of labor supply

    """
    mu = (1.0 / l_tilde) * ((n / l_tilde) ** theta)

    return mu