High arrival delay at major airports tends to propagate and generate secondary delay through the National Airspace System (NAS). In the United States, it is widely believed that the major culprits for delay throughout the NAS are the three New York commercial airports – Newark (EWR), LaGuardia (LGA), and John F. Kennedy (JFK). Various estimates of the extent to which the New York airports impact the delay in the NAS have been reported over the years. Yet there is no thorough investigation into the mutual relationship between delays at New York and non-New York airports. In this paper, we take two different approaches to quantify the impact of the three New York airports on delay throughout the NAS. First, we estimate and apply an econometric model using a large historical dataset. The other model is the FAA SWAC model that simulates flights and tracks the daily performance of the system. The counterfactual scenarios in these two models are adjusted to be comparable to each other. There is disparity between the results of the two different models, suggesting the simulation model might not capture all the factors that cause arrival delay. Still both results conclude that the portion of delay in the system caused by New York airports is much less than publicized estimates. Combining econometric and simulation models to address questions of this nature appears to be a promising approach.