on its employment forecast when a vice president for the company told CNN last fall that the 20,000 jobs Keystone would create were temporary and that the project would likely yield only "hundreds" of permanent positions. Another reason for the discrepancy appears to stem from what that 20,000 figure really means. As Transcanada has conceded, its estimate counted up "job years" spent on the project, not jobs. In other words, the company was counting a single construction worker who worked for two years on Keystone as two jobs , lending fuel to critics who said advocates of the pipeline were overstating its benefits. The Cornell researchers concluded: The construction of KXL will create far fewer jobs in the U.S. than its proponents have claimed and may actually destroy more jobs than it generates.... The claim that KXL will create 20,000 direct construction and manufacturing jobs in the U.S. is unsubstantiated. There is strong evidence to suggest that a large portion of the primary material input for KXL -- steel pipe -- will not even be produced in the U.S. In a statement, President Obama attributed the decision to block construction of the pipeline to "the rushed and arbitrary deadline insisted on by Congressional Republicans," saying it "prevented a full assessment of the pipeline's impact, especially the health and safety of the American people, as well as our environment." The furor is likely to continue, highlighting the intense election-year politics around Keystone. In urging Obama to approve the project, for instance,