NEW YORK: US millennials, especially those of Hispanic descent, are more optimistic than they were last year about their country's future, according to the US segment of a new global survey.

The second Global Millennial Survey commissioned by Telefónica, the Spanish telecoms company, questioned just over 6,700 young adults aged 18 to 30 in 18 countries, including 1,000 millennials in the US, half of them Hispanic.

It found an average of over half (51%) of young American adults believe their country's best days lie ahead compared to 44% in last year's inaugural survey. This opinion is shared by 58% of Hispanics and 49% of non-Hispanics.

Overall, 89% are "generally optimistic" about their futures and 43% say they're "very optimistic" compared with 35% last year.

However, they have concerns about the economy and society that go beyond their individual interests. Over a quarter (26%) view the economy as the most important issue facing the US today and 77% believe wealth inequality is growing.

Corruption (47%), political leadership (38%) and the education system (38%) are perceived to be the biggest barriers to the country's growth.

And they believe that equal opportunities for all (32%) and a strong education system (28%) are the key to domestic growth.

While more than half (59%) are satisfied with the education system, two-thirds (66%) are concerned about its affordability, although quality of teachers (53%) and quality of curriculum (52%) also worry them.

Turning to their adoption of technology, the survey found US millennials own more mobile devices than last year.

Nearly four-in-five (79%) now own a smartphone (up from 70%), 56% own a tablet (up from 37%) and 58% use these devices primarily for entertainment.

When it comes to deciding on whether to buy a technology brand, more than a third (34%) say commitment to sustainability and social impact is very important.

The adoption of mobile devices by this generation is mirrored elsewhere in other parts of the world, the survey found.

Among young Brazilian adults, 78% use smartphones and 42% use tablets while the statistics for millennials in Western Europe are 84% and 40% respectively, Telecompaper reported.

In Brazil, smartphones are used for social networks (68%), news (60%), phone calls (57%), text messages (56%), online videos (51%), posting videos (40%), making videos and taking photos (37%), playing games (31%) and streaming videos (30%).

Smartphones are used by nearly a quarter (24%) to make a financial transaction and by 20% to make a purchase.

Data sourced from Telefónica; additional content by Warc staff