Airports are a linchpin in the nation’s air transportation system. Adequate and predictable funding is needed for airport development. The National Civil Aviation Review Commission—established by Congress to determine how to fund U.S. civil aviation—reported in December 1997 that more funding is needed to develop the national airport system’s capacity, preserve small airports’ infrastructure, and fund new safety and security initiatives. Funding is also needed to mitigate the noise and other negative environmental effects of airports on nearby communities. Airports provide important economic benefits to the nation and their communities. Air transportation accounted for $63.2 billion, or 0.8 percent, of U.S. Gross Domestic Product in 1996, according to the Department of Transportation’s statistics. 1.6 million people are employed at airports in 1998, according to the Airports Council International-North America. In our own study of airport privatization in 1996, we found that the 69 largest U.S. airports had 766,500 employees (686,000 private and 80,500 public employees). In 1996, tax-exempt bonds, the Airport Improvement Program (AIP), and passenger facility charges (PFC) together provided about $6.6 billion of the $7 billion in airport funding. State grants and airport revenue contributed the remaining funding for airports. Table 1 lists these sources of funding and their amounts in 1996. The amount and type of funding varies with airports’ size. The nation’s 71 largest airports (classified by FAA as large hubs and medium hubs), which accounted for almost 90 percent of all passenger traffic, received more than $5.5 billion in funding in 1996, while the 3,233 other national system airports received about $1.5 billion. As shown in figure 1, large and medium hub airports rely most heavily on private airport bonds, which account for roughly 62 percent of their total funding. By contrast, the 3,233 smaller national system airports obtained just 14 percent of their funding from bonds. For these smaller airports, AIP funding constitutes a much larger portion of their overall funding—about half. Airports’ planned capital development over the period 1997 through 2001 may cost as much as $10 billion per year, or $3 billion more per year than in 1996. Figure 2 compares airports’ total funding for capital development in 1996 with their annual planned spending for development. Funding for 1996, the bar on the left, is shown by source (AIP, PFCs, state grants, and operating revenues). Planned spending for future years, the bar on the right, is shown by the relative priority FAA has assigned to the projects, as follows: Reconstruction and mandated projects, FAA’s highest priorities, total $1.4 billion per year and are for projects to maintain existing infrastructure (reconstruction) or to meet federal mandates, including safety, security, and environmental requirements, including noise mitigation requirements. Other high-priority projects, primarily adding capacity, account for another $1.4 billion per year. Other AIP-eligible projects, a lower priority for FAA, such as bringing airports up to FAA’s design standards, add another $3.3 billion per year for a total of $6.1 billion per year. Finally, airports anticipate spending another $3.9 billion per year on projects that are not eligible for AIP funding, such as expanding commercial space in terminals and constructing parking garages. Other high-priority projects $1,360 Reconstruction & mandates $1,414 Planned development 1997 through 2001 (annualized) Within this overall picture of funding and planned spending for development, it is difficult to develop accurate estimates of the extent to which AIP-eligible projects are deferred or canceled because some form of funding cannot be found for them. FAA does not maintain information on whether eligible projects that do not receive AIP funding are funded from other sources, deferred, or canceled. We were not successful in developing an estimate from other information sources, mainly because comprehensive data are not kept on the uses to which airport and special facility bonds are put. But even if the entire bond financing available to smaller airports were spent on AIP-eligible projects, these airports would have, at a minimum, about $945 million a year in AIP-eligible projects that are not funded. Conversely, if none of the financing from bonds were applied to AIP-eligible projects, then the full $3 billion funding shortfall would apply to these projects. The difference between current and planned funding for development is bigger, in percentage terms, for smaller airports than for larger ones. Funding for the 3,233 smaller airports in 1996 was a little over half of the estimated cost of their planned development, producing a difference of about $1.4 billion (see fig. 3). This difference would be even greater if it were not for $250 million in special facility bonding for a single cargo/general aviation airport. For this group of airports, the $782 million in 1996 AIP funding exceeds the annual estimate of $750 million for FAA’s highest-priority projects—those involving reconstruction, noise mitigation, and compliance with federal mandates. However, there is no guarantee that the full amount of AIP funding will go only to the highest-priority projects, because one-third of AIP funds are awarded to airports on the basis of the number of passengers boarding commercial flights and not necessarily on the basis of projects’ priority. Planned development 1997 through 2001 (annualized) As a proportion of total funding, the potential funding difference between 1996 funding and planned development for the 71 large and medium hub airports is comparatively less than for their smaller counterparts (see fig. 3 and fig. 4). Larger airports potential shortfall of $1.5 billion represents 21 percent of their planned development costs, while smaller airports’ potential shortfall of $1.4 billion represents 48 percent of their development costs. Therefore, while larger and smaller airports’ respective shortfalls are similar in size, the greater scale of larger airports’ planned development causes them to differ considerably in proportion. Figure 4 also indicates that $590 million in AIP funding falls $74 million short of the estimated cost to meet FAA’s highest priorities for development—reconstruction, noise mitigation, and compliance with federal mandates. Planned development 1997 through 2001 (annualized) Proposals to increase airport funding or make better use of existing funding vary in the extent to which they would help different types of airports and close the gap between funding and the costs of planned development. For example, increasing AIP funding would help smaller airports more because current funding formulas would channel an increasing proportion of AIP to smaller airports. Conversely, any increase in PFC funding would help larger airports almost exclusively because they handle more passengers and are more likely to have a PFC in place. Changes to the current design of AIP or PFCs could, however, lessen the concentration of benefits to one group of airports. FAA has also used other mechanisms to better use and extend existing funding sources, such as letters of intent, state block grants, and pilot projects to test innovative financing. So far, these mechanisms have had mixed success. Under the existing distribution formula, increasing total AIP funding would proportionately help smaller airports more than large and medium hub airports. Appropriated AIP funding for fiscal year 1998 was $1.7 billion; large and medium hub airports received nearly 40 percent and all other airports about 60 percent of the total. We calculated how much funding each group would receive under the existing formula, at funding levels of $2 billion and $2.347 billion. We chose these funding levels because the National Civil Aviation Review Commission and the Air Transport Association (ATA), the commercial airline trade association, have recommended that future AIP funding levels be stabilized at a minimum of $2 billion annually, while two airport trade groups—the American Association of Airport Executives and the Airports Council International-North America—have recommended a higher funding level, such as AIP’s authorized funding level of $2.347 billion for fiscal year 1998. Table 2 shows the results. As indicated, smaller airports’ share of AIP would increase under higher funding levels if the current distribution formula were used to apportion the additional funds. Increasing PFC-based funding, as proposed by the Department of Transportation and backed by airport groups, would mainly help larger airports, for several reasons. First, large and medium hub airports, which accounted for nearly 90 percent of all passengers in 1996, have the greatest opportunity to levy PFCs. Second, such airports are more likely than smaller airports to have an approved PFC in place. Finally, large and medium hub airports would forego little AIP funding if the PFC ceiling were raised or eliminated. Most of these airports already return the maximum amount that must be turned back for redistribution to smaller airports in exchange for the opportunity to levy PFCs. If the airports currently charging PFCs were permitted to increase them beyond the current $3 ceiling, total collections would increase from the $1.35 billion that FAA estimates was collected during 1998. Most of the additional collections would go to larger airports. For every $1 increase in the PFC ceiling, we estimate that large and medium hub airports would collect an additional $432 million, while smaller airports would collect an additional $46 million (see fig. 5). In total, a $4 PFC ceiling would yield $1.9 billion, a $5 PFC would yield $2.4 billion, and a $6 PFC would yield $2.8 billion in total estimated collections. Increased PFC funding is likely to be applied to different types of projects than would increased AIP funding. Most AIP funding is applied to “airside” projects like runways and taxiways. “Landside” projects, such as terminals and access roads, are lower on the AIP priority list.