These are not adequate comparisons.
See, first, the pure "statistical significance" of the differences is not the important thing here, this is an estimation problem, not a test problem.
But, even if statistical significance were the most important thing, both comparisons are wrong.
For example, do you think that growth rates and debts between countries are independent? If they aren't, then the relationship between individual CI's and differences CI's can be very odd, not only in the way mentioned in the paper you have linked. So, all these "eyeballing" tests are misleading.