Bloomberg published their predictions for the top forty most densely populated cities by 2025, with current #1 Hong Kong keeping the top spot, at nearly twice the projected density of #2, Salvador, Brazil. Hong Kong's population growth is predicted to grow by 32.8%, while Salvador's is nearly triple that rate at a 97.3% increase. Mexico City is #3, at 45.3% increase. The "crowded" metric is population per square mile, assuming that borders don't change (by land erosion or reclamation) by 2025.

Of the Top 40, the two cities with the highest estimated population growth (within the span of the generation leading up to 2025) are both in Saudi Arabia: Riyadh (166.6% increase) and Jiddah (137.4% increase), trailed by Brasilia, Brazil at 118.6%. The only other city with a projected growth of more than 100% is Atlanta, Georgia, at 114.7% population growth to become the 40th most crowded city by 2025.

The cities with the lowest projected population growth are: Seoul-Incheon, South Korea at 1.4% growth; St. Petersburg, Russia at 6.4% growth; and Keihanshin, Japan, at 8.6% growth. For comparison, #1 Hong Kong is projected to have 76,985 people per square mile in 2025, approximately 34 times as many people per square mile as #40, Atlanta, Georgia.

Some surprises: both Los Angeles and San Francisco outrank New York by approximately 1,000 people per square mile; Hong Kong is the only Chinese city to be listed; no Indian cities made the list.