The
historical daily index data for US S&P 500, EAFE (Europe, Australia, Far
East) and EM (Emerging Markets) from January 2, 2017 through November 5, 2018.
There are 480 points in total.
After
that I computed the daily return for each index using the return formula:
For
convenience I keep all in decimal form instead of percentage. So I did not
multiple 100 in the above formula. Then I computed the average and standard
deviation for each return series, as well as the correlation between them.
Suppose the weights of USA S&P 500 index and EAFE index in the
international portfolio are a and 1-a respectively
The
international portfolio using USA and EAFE is shown in Appendix A. We can see
that the standard deviation can be as low as 0.521% although each of USA and
EAFE has a higher standard deviation. This effect is called diversification due
to the imperfect correlation between the two indices. As long as the
correlation coefficient is not 1, we can always have some degree of diversification
effect.
The
international portfolio using USA and EM is shown in Appendix B. Similar to the
above portfolio, we also see diversification effect in this portfolio. The
standard deviation can be as low as 0.620% although each of USA and EM has a
higher standard deviation.
I
computed rp and p for a=weight (0, 0.1, 0.2, 0.3, ..., 1). These weights
change in ten percent increments, so there are eleven combinations to compute
for the risk and return that can be graphed.
The international portfolio diversification is
way to minimize risk and maximizing the return. The portfolio is created so
that the level of risk can be minimized. If the investor is going to invest in
only one security than the chances of financial loss are quite higher. Therefore
investing in different securities would lead to significant amount of return.