Today, just four companies—Walmart, Kroger, Costco and Albertsons—account for about half of all grocery sales in the country. And two of them, Kroger and Albertsons, want to merge. If approved, it would be the largest supermarket merger in history. Together they employ 700,000 people across some 5,000 stores. But regulators are fighting back, arguing that a merger would be bad for consumers and for workers.

In this episode we go inside the courtroom to hear the case for and against the merger with Laurel Kilgour, an attorney and the research manager at the American Economic Liberties Project.