Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We studied the market performance at selected, representative natural gas trading hubs in the U.S. and documented different price behaviors among various hubs. With NYMEX prices as the competitive benchmark, we found empirically that the spot price responses at some trading hubs were systematically asymmetric, thus demonstrating a market advantage by either buyers or sellers. We further found that the presence of market power was a very plausible explanation for this price behavior at some hubs.