LINK >>> http://www.ncpa.org/pdfs/st340.pdf
The study continues at the link above.
Executive Summary
Grocers and other retailers nationwide pack consumers’ purchases in plastic bags. However, a growing number of jurisdictions — including Los Angeles County, and cities such as Austin and Seattle — have banned the use of thin-film plastic bags. Other local governments, such as the Washington, D.C., city council, have implemented a per-bag tax.
In July 2011, the Los Angeles County bag ban took effect for large grocery and retail stores in some areas of the county. In January 2012, the ban took effect for smaller grocery and convenience stores. The ban did not apply to any stores in incorporated areas of Los Angeles County. The National Center for Policy Analysis conducted a survey of store managers in both areas, regarding the plastic bag ban. This study reports those results.
The purpose of the survey was to determine the effects of the ban on sales and employment at the stores affected by the ban. The study also sought
to determine if consumers changed their shopping behavior by increasing purchases at stores that could still offer plastic bags. The survey found
that following full implementation of the ban, sales increased at stores in incorporated cities compared with stores in unincorporated areas. Of these respondents to the survey affected by the ban:
■ Over a one-year period (pre- and post-bag ban), 60 percent of stores in incorporated areas reported an increase in sales averaging 9 percent.The ban negatively affected employment at stores inside the ban area. While every store inside the ban area was forced to terminate some of its staff, not a single store outside the ban area dismissed any staff. Stores inside
■ Fourth-fifths of the stores in the unincorporated areas reported a decrease in sales averaging, –5.7 percent.
Examining the overall change in sales of all the stores that responded among the two groups (incorporated versus unincorporated):
■ Incorporated stores experienced an increase in sales of 3.4 percent.
■ However, unincorporated stores reported a decline in sales of –3.3 percent.

A Survey on the Economic Effects of Los Angeles County’s Plastic Bag Ban
the ban area reduced their employment by more than 10 percent. Stores outside the ban area increased their employment by 2.4 percent.