Every four years, economists at Goldman Sachs take a short break from their usual chores to take a stab at estimating the Olympic medal tallies. With the spectacle in Rio days away, the economists have a prediction: Countries boasting healthy economic fundamentals will outperform.

"In general, gold does go to where the growth environment is best," the investment bank summed up in a new report, referring to the economic, political and institutional factors that affect a nation's productivity performance.

According to its model, the world's two-largest economies are set to clinch the largest medal hauls at Rio de Janeiro.

The U.S. could walk away with 106 medals in total, including 45 gold ones, GS said, not far off from the country's 2012 performance of 104 overall medals. Should Goldman's forecasts materialize, it would mark the second consecutive Olympics that the U.S. finishes at the top of both the gold and overall medal standings.

GS estimates that China will finish second in the medals tally, with 89 total medals, out of which 36 are expected to be gold. In 2012, China also ranked second to the U.S. in terms of the highest gold and overall medal count.

"Unsurprisingly, the U.S. and China dominate the table, but there is an important difference," GS observed.

U.S. dominance is focused on sports with the most events and medals on offer, such as swimming and athletics, whereas China has the largest margin of leadership in the sports it is best at, including table tennis, badminton and diving, GS explained.

The U.K. is tipped to finish third on GS's list with 59 medals, 23 of which are expected to be gold, followed by Russia's medal count of 58, including 14 gold medals. Brazil, the host country, is expected to secure 22 medals in total - which would mark its best achievement at the summer games ever.

It's not just the Olympic giants—China and the U.S.—that dominate all sports; Italy, South Korea and Brazil are also worth keeping an eye on, GS noted.

"With a dominance score of 44 percent, South Korean archers have been the team to beat for several Olympic Games (South Korea also dominates taekwondo but by a much smaller margin). Similarly, Italian fencers—excuse the bad pun—have been at the cutting edge of the sport for many Games. And Brazil has been dominating the volleyball competition over the last couple of Olympic Games."

Economists often try to identify the process by which countries experience income growth, specifically who's falling behind and forging ahead. The same mindset can be applied to Olympic sports, GS said.