JFK gains and LGA lossses

I've been checking out the Port Authority's website lately and I notice that JFK has really been gaining traffic with both passengers and movements. Some months, it even surpasses EWR in terms of aircraft movements.

LGA, on the other hand, has been steadily losing traffic the last year or so. It's still congested and busy, but the PA's website shows that traffic has declined.

So what gives? Is it that some airlines are moving their flights from LGA to JFK? Or is JFK just gaining traffic on it's own merits? And why is LGA losing traffic?

My guess is because JFK has the capacity to hold more flights than LGA and because the slot restrictions (if any at JFK) are not as harsh at JFK, because they are very strict at LGA.

JFK has been gaining quite a bit of international traffic with the expansion by Delta and new services from Emirates and Etihad.

LGA maxed out just prior to 911. It was more than a "mess". The airport reached the absolute limit - too many flights with RJs and such.

I watched consecutive go arounds one day. That won't happen again; it doesn't work.

JFK was underutilized. It wasn't particurlary busy at all in the mornings, and there was more space available. Jetblue opened it up again, and the rest has gradually increased as well.

EWR is both out of both space on the ground as well as the ability to land more than a tiny fraction of the aircraft than they already do.

Tom

The carriers that expanded service into JFK have well. Not to mention, the new runway configurations they use during rush hour have considerably decreased the delays in spite of the increased traffic.

Yeah, LGA has had it's problems with congestion and everything and before 9/11, it was intolerable. But it doesn't really explain why traffic has gone down there the last year or so.