Millennials are a “generation lost,”according to a new study, and are in for a tough time when theyfinally reach retirement, thanks to a lack of understanding offinancial matters as much as a lack of interest.

The study, titled “Generation Lost: Engaging Millennials withRetirement Saving,” from BNY Mellon and a team of students fromCambridge Judge Business School, University of Cambridge, foundthat millennials internationally will have a more difficult time inretirement because of demographic, political, and macroeconomictrends.

Read: Student loans cripple millennials' retirementsaving efforts

Nearly half—46 percent—of millennials aren’t getting anyinformation on financial matters, either through theworkplace or through the educationsystem.

In addition, 51 percent are calculating what they’ll need inretirement via a “blind guess” rather than anything actuallyresembling calculations.

Industry data didn’t enter into their assumptions. Another 39percent have settled on a number via an “educated guess.”

Sixty-three percent said they’d save more if their pensionallowed multiple lifetime withdrawals. The most important lifeevents for which millennials would want access to cash through sucha product are the need to put a down payment on a house (49percent) or being faced with the expenses of a major illness (48percent).

And while globally 77 percent said they wanted to be told the“stark reality” of what they will face financially in retirement,that varied pretty widely depending on their country of origin.

For instance, only 48 percent of Brazilian millennials want toknow the “stark reality,” compared to 94 percent ofAustralians.

Millennials also said that they’d allocate 42 percent of theirportfolios to social finance products (socially responsibleinvesting), if they had the option.

However, they don’t think much of what’s available; 95 percentof millennials globally feel that pension funds and insurersprovide limited, poor, or no options for investing in socialfinance products.