The recent California's energy crisis has raised doubts about the benefits of energy deregulation. While it is true that the California electricity market is in turmoil, other electricity markets like the Pennsylvania-NewJersey-Maryland (PJM) are doing fine. This paper assesses the mark of efficiency reached by the electricity markets in California, New York, and PJM. It also compares the degree of efficiency across markets (forward vs. real time) and across time. No significant differences between the California and PJM electricity markets were discovered in the year of California's energy crisis (2000) using the cointegration tests. This research suggests that differences in price behavior between these two markets during 2000 did not arise from differences in efficiency. According to our analysis and measures of efficiency, PJM and California electricity markets are more efficient than the New York market. Also, as these markets become more mature over time, their efficiency level goes up. We also found evidence that a multi-settlement scheduling system leads to higher efficiency.