Estimating the cost of strategic entry delay in pharmaceuticals: The case of Ambien CR

With the Hatch-Waxman Act of 1984, the FDA included an unchallengeable exclusivity period for newly approved drugs, independent of patents. This potentially generates an incentive for firms to strategically delay the introduction of new versions (reformulations) of drugs until just before patent expiration of the original drug. This way the reformulated drug competes mainly with newly introduced generics of the original drug. If instead, the...