A new report finds the bag tax that Washingtonians have been paying for more than a year now to be a job killer and economic loser. The study, commissioned by Americans for Tax Reform and conducted by the Beacon Hill Institute, examines the economic fallout of the D.C. bag tax.

One of the more annoying taxes ever devised, the levy covers even those little plastic bags that Subway puts your foot-long in. Macy's has to charge a bag tax with all purchases storewide for the simple reason that it sells Godiva chocolates.

According to the report, the bag tax will result in the elimination of more than 100 local jobs and precipitate a $5.64 million decline in aggregate disposable income for 2011. The majority of this income would have been spent in the District and, as a result of the bag tax, D.C. will now needlessly forgo an additional $108,340 in sales tax revenue and will see investment drop by $602,000, with the bulk of the loss occurring in the retail sector.

The report's findings underscore that the bag tax takes its greatest toll on the District's poorest residents and communities. Unlike many bag tax supporters, D.C.'s poor and elderly who rely on public transportation aren't likely to have a Subaru Outback or Volvo station wagon in which to keep all of their Life is Good canvas bags handy. And despite the green auspices under which bag taxes and bans are sold, it has yet to be demonstrated that they produce any measurable environmental benefit.

As it stands, the environmental impact wrought by plastic bag taxes and bans is equivalent to the ratio of unicorns to leprechauns in the District -- zero. Litter audits conducted before and after San Francisco's first-in-the-nation bag ban found that while plastic bags were not a significant source of litter to begin with, plastic bags actually ended up comprising a greater share of total litter after the ban.

The report crystallizes the dubious economic impact of the bag tax, but bag taxes and bans have other unintended consequences, some of which even pose a public health risk.

Scientific testing of reusable shopping bags found that they are often used for multiple purposes and "seldom if ever washed," making them a Petri dish for bacteria and cross-contamination. Researchers discovered large quantities of bacteria "in almost all bags and coliform bacteria in half."

Who's hungry now? I know I am.

The health concerns don't end there. A Tampa Tribune investigation in November found that certain types of reusable bags sold at Publix and Winn-Dixie contained levels of lead that health officials deemed a cause for concern.

The issue has even drawn the attention of Congress. Sen. Chuck Schumer, D-N.Y., recently called on the Food and Drug Administration, the Environmental Protection Agency, and Consumer Product Safety Commission to investigate the matter.

"When our families go to the grocery store looking for safe and healthy foods to feed their kids, the last thing they should have to worry about are toxic bags," said Schumer.

Despite evidence that bag taxes and bans are detrimental to the economy and do not improve the environment, anti-plastic zealots continue an aggressive, well-funded lobbying campaign in state capitols and city halls across the country.

The Oregon Senate is considering a bill that would impose the first statewide bag prohibition in the U.S. While a bag tax or ban may not have been proposed in your neck of the woods -- don't worry -- chances are that it will be in the near future. This new report on D.C.'s experience should serve as a cautionary tale.

Patrick Gleason is director of state affairs at Americans for Tax Reform.