LINCOLN, Neb. — Attorney General Doug Peterson again sought to discredit a study that says Nebraska’s death penalty costs $14.6 million per year, while the economist who conducted it stood by his work Wednesday.

The Republican attorney general, who supports the death penalty and has criticized the Legislature’s decision to abolish it, said the study inflated the defense and housing costs for death row inmates, as well as the number of court days spent on capital punishment cases.

“There are serious inaccuracies contained in this report,” Peterson said at a news conference less than two months before voters will decide whether to overturn the state’s ban on the death penalty in the November general election.

Creighton University economist Ernie Goss said his study is scientifically valid, based on U.S. census data and is generally accurate. He was hired to do the report by death penalty opposition group Retain a Just Nebraska.

Peterson said the report falsely claims that seating a jury and imposing a sentence in a death penalty case can take weeks, countering that the average time in Nebraska to select a jury for the current death row inmates was three days and to impose the sentence was 3.6 days.

But Goss’ study doesn’t say that seating a jury or imposing a sentence takes weeks in Nebraska, instead citing averages drawn from a separate study of Colorado’s criminal justice system, which concluded that capital punishment cases take longer than others.

When it comes to the price of the death penalty, Goss said he looked at average spending by states with the death penalty and those without for 2012 and 2013, the latest years with available data. His comparison showed that states with capital punishment generally spend more, and then he adjusted the numbers to account for differences among states, such as prison population, per-capita income, geography and minority and religious populations.

“I did not calculate a bunch of these little things together and add them up,” he said. Death penalty supporters are “using anecdotal data. When you use anecdotal data, the margins of error are really huge.”

Goss also stressed that his study only addressed the financial costs of the death penalty, not the moral, ethical or religious issues. The conservative economist has refused to discuss his personal feelings about the punishment.