It took me a little while to figure out that your one-word post meant the practice of selling below cost to gain market share, with the intent to force marginal competitors out of your business and gain pricing power to be used later to make up for the losses.
I am not convinced that this practice is worthy of concern. I don't think that a short-term predatory pricing loss incurred by a dumper can ever be recovered. This opinion is based mostly on the personal belief that the substitution effect is far greater than most economists care to admit, particularly when the potential substitution is to not buy anything at all.
You can't dump alfalfa to bankrupt existing hay growers and then make a killing by raising alfalfa prices once you dominate the market. Why? Farmers will feed their livestock gummy bears[0]. And then they will plant their own damned hay crops at the very next available opportunity. The net result is that you go bankrupt, too, because you took a huge loss right before killing your own market.
