FAQ - FREQUENTLY ASKED QUESTIONS
AIRPORT LEAKAGE SCORECARD REPORT
4) IS MY AIRPORT DOING WELL OR POORLY?
5) THE POPULATION FOR MY AIRPORT IS TOO HIGH/LOW?
6) THE TRAFFIC FOR MY AIRPORT IS TOO HIGH/LOW?
2) HOW DO I READ THIS REPORT?
This report shows population and Resident traffic for the most recent quarter for all U.S. airports. The population is based on a 30 mile ring around the airport with all postal codes centered within 30 miles included in the population. This is irrespective of drive time. An airport with a large body of water like New Haven (HVN) will include population (e.g. Long Island) if it is within 30 miles even if the travel time from the island is lengthy. This is an imperfection, but is too complex to correct. Resident traffic is based on total DB1B traffic data for the airport, using the first trip of the passenger's full ticket to determine residence airport. A polynomial regression line shows the average relationship between Resident traffic and population for the U.S. Since "leakage", or the net number of passengers using a different airport within the 30 mile catchment region of an airport, has to balance to zero, the line is intended to show what level of resident traffic represents zero net leakage is for an airport with that population level based upon all U.S. airports. Of course, that is also not perfect. Some regions have higher or lower propensity to travel based on factors like weather or income, but it is a proxy.
Generally airports above the regression line and shown in GREEN are net gainers in resident leakage and airports below the line shown in RED are net losers. The further they are from the line, the larger the imbalance. Said another way, RED airports are underserved, and GREEN airports are overserved relative to their population. The assumption is that visitor traffic likely behaves like resident traffic.
3) WHAT IS CATCHMENT/LEAKAGE?
Catchment is the area around an airport where most of the airport's traffic should be generated from or headed to. Airports are very concerned about how much passenger traffic they are getting because without enough passenger traffic and airport doesn't get the routes it wants. There are three ways to boost passenger traffic: 1) stimulate demand with low fares or new routes, 2) steal traffic from the area around other airports, and 3) reduce the amount of traffic around your airport "leaking" to another airport. For example, a passenger in Mobile (MOB/BFM) drives to Pensacola (PNS) for a non-stop to Nashville (BNA). That is Negative Leakage from MOB/BFM to PNS. Net Leakage is the #2 minus #3. Airports generally want at least ZERO Net Leakage, but small airports often leak as much as 90% of the traffic in the area around their airport to other airports with lower fares or better service. For the purposes of this analysis, we only consider passengers in a 30 mile ring around the airport for determining whether the airport is Net Positive or Net Negative on Leakage.
4) IS MY AIRPORT DOING WELL OR POORLY?
Generally airports above the regression line and shown in GREEN are net gainers in resident leakage and airports below the line shown in RED are net losers. The further they are from the line, the larger the imbalance. Said another way, RED airports are underserved, and GREEN airports are overserved relative to their population. The assumption is that visitor traffic likely behaves like resident traffic.
5) THE POPULATION FOR MY AIRPORT IS TOO HIGH/LOW?
The population is based on a 30 mile ring around the airport with all postal codes centered within 30 miles included. This is irrespective of drive time. An airport with a large body of water like New Haven (HVN) will include population (e.g. Long Island) if it is within 30 miles even if the travel time from the island is lengthy. This is an imperfection, but is too complex to correct.
6) THE TRAFFIC FOR MY AIRPORT IS TOO HIGH/LOW?
O&D resident traffic is shown. It is not enplaned and it does not include visitors either. This is because there is the strongest mathematical correlation between leakage and resident traffic compared to population. Connecting traffic and visitors do not relate to population. Resident traffic is based on DB1B data, using the first trip of the passenger's full ticket to determine residence airport.
7) WHAT IS THE LINE THROUGH THE DATA?
A polynomial regression line shows the average relationship between Resident traffic and population for the U.S. Since "leakage", or the net number of passengers using a different airport within the 30 mile catchment region of an airport, has to balance to zero, the line is intended to show what level of resident traffic represents zero net leakage is for an airport with that population level based upon all U.S. airports.
8) THE AVERAGE LINE IS WRONG?
Some regions have higher or lower propensity to travel based on factors like weather or income, but it is a proxy. There is no perfect measure.
9) DOES THIS INCLUDE INTERNATIONAL?
This is only based on domestic data, however, international O&D traffic is usually 15% or less of total traffic, so the inclusion of the leakage on that 15% is probably not enough to change the graph except at very large international airports like JFK and LAX. Even at an airport like Providence (PVD), in the shadow of Boston (BOS), the graph would probably look nearly the same because even if the leakage rate on intl is 2x the rate on domestic the relative position on the graph probably changes little because of the 85% traffic weighting to domestic.