Hawai'i has the second-highest rate of online pornography subscribers in the nation, a new study says.

The study by Benjamin Edelman of Harvard Business School calculated Hawai'i's rate at 1.37 subscribers per 1,000 residents. When looking at homes with Internet users, the rate is 2.19 subscribers per 1,000 homes.

Only Utah has higher rates in both categories, and that state topped two other categories in the study, which collected data from two years of credit-card purchases from adult entertainment Web sites.

The study also found that states that tend to be more conservative and religious are paying to watch slightly more porn than more liberal states.

However, "when it comes to adult entertainment, it seems people are more the same than different," Edelman told the magazine NewScientist. The study was published in the current edition of the Journal of Economic Perspectives.

Eight of the top 10 pornography-consuming states gave their electoral votes to John McCain in last year's presidential election — Florida and Hawai'i were the exceptions. On the other hand, six out of the lowest 10 favored Barack Obama.

Churchgoers bought less online porn on Sundays — a 1 percent increase in a postal ZIP code's religious attendance was associated with a 0.1 percent drop in subscriptions that day. But expenditures on other days of the week brought them in line with the rest of the country, Edelman found.

Residents of 27 states that passed laws banning gay marriage boasted 11 percent more porn subscribers than states that don't explicitly restrict gay marriage.

The study also found slight differences in online porn purchasing habits, based on education, urbanization and income.