The Plastic Bag Argument: Concession and Rebuttal
An argument passage considers a proposed city ban on single-use plastic bags. The author writes, 'The ban would impose real costs on small grocers, and I do not dismiss those costs. A store owner I interviewed estimated $3,000 in new expenses for reusable bags and staff training.' The next paragraph begins, 'But cost is not the only measure.' The author then cites a neighboring city where bag litter fell 40 percent after a ban and argues that the fee revenue can offset grocer costs. A candidate annotates the first sentence as 'author's main claim' and writes that the passage 'mostly agrees with the grocers.' The candidate also says the concession weakens the argument because it admits a problem. The instructor asks the candidate to identify the author's actual claim, explain the concession's function, and judge whether the evidence after 'But' answers the objection.
1. Identify the author's main claim and explain the function of the sentence about grocer costs.
Read the worked answer
The main claim comes after the concession: the ban's environmental benefit and the fee-revenue offset make it worthwhile despite costs-more precisely, cost is not the only measure and the ban should be judged on litter reduction plus offsettable expenses. The grocer-cost sentence is a concession that establishes the author's awareness of a real objection. It is not the main claim, even though it is the first sentence.
Its function is to build credibility and set up the rebuttal: the author grants an economic cost, then argues the cost is not decisive. The candidate's annotation mistakes a concessive premise for the thesis.
2. The candidate says the concession weakens the argument because it admits a problem. Evaluate that judgment.
Read the worked answer
The judgment is too simple. A concession can weaken an argument if the admitted problem is left unanswered or if it contradicts the thesis. Here the author answers it with fee revenue and a litter reduction in a neighboring city. The concession may actually strengthen credibility by showing the author is not glossing over costs. It also narrows the disagreement: the author agrees costs exist but disputes their decisiveness.
Whether the rebuttal succeeds depends on whether the $3,000 estimate is typical and whether fee revenue actually reaches grocers. The concession itself is not a flaw; the unanswered details are the place to press.
3. Does the evidence after 'But' answer the objection? What additional information would make the argument stronger?
Read the worked answer
It answers the objection only partly. The 40 percent litter drop supports the environmental benefit, and fee revenue is a plausible offset, but the passage does not show that the revenue covers the $3,000 figure or that the interviewed owner is representative.
Stronger support would include average compliance costs across several small grocers, data on how fee revenue is distributed, and litter measurements from more than one city. The argument would also be stronger if it addressed enforcement costs and whether low-income shoppers bear a disproportionate burden. The 'But' paragraph responds to the objection's relevance, not yet to its magnitude.