PRICING OF AIRPORT SERVICES ACCORDING TO PRINCIPLES OF WELFARE ECONOMICS Mathisen, T. A., Jørgensen, F. and Solvoll, G. Bodø Graduate School of Business at University of Nordland NO-8049 Bodø, Norway 1. INTRODUCTION Airport infrastructure is, in most countries, financed by airport charges put on the services produced at the airport together with revenues from commercial activities. The international air transport organizations aim for standardization of the airport charges (Martin-Cejas, 1997) and ICAO (2009) has a general policy stating that charges, amongst other things, should be based on costs and be non-discriminatory. Most airports charge both passengers (PAX) and air traffic movements (ATM) but there are variations with respect to the distribution of charges between PAX and ATM both between countries and type of ownership. The major part of the Norwegian airports is operated by the state owned company Avinor. These airports are operated commercially and do not in total require state subsidies, but there is some cross-subsidization between the largest airports and those located in rural areas. The Norwegian Ministry of Transport and Communication initiated in 2010 a project to evaluate the charges that generate the airports’ traffic revenues. This paper presents the main results from this project. The aim of the paper is to analyze the Norwegian airports’ costs structure and subsequently derive the marginal cost of serving passengers and airplanes. Taking the marginal cost estimations as a starting point, the paper suggests a revised scheme for aviation charges designed according to principles welfare economics. The further organization of the paper is: Section 2 provides a brief presentation of the Norwegian airport infrastructure with special focus on how it currently is financed. Then, Section 3 discusses an econometric model suitable for studying costs at Norwegian airports. Next, Section 4 gives details about the data set, presents model results and derives marginal costs for PAX and ATM. The results are applied in new schemes for airport charges in Section 5 where the cost of raising public funds also is taken into account. Finally, possible implications for air transport companies, passengers and the authorities by implementing these airport charges are briefly discussed in Section 6. 2. NORWEGIAN AIRPORTS AND AIRPORT CHARGES 2.1 The Norwegian Airport Structure Today Norway is amongst the countries in Europe with the highest air transport dependence (Williams et al., 2007). While Norway in 2003 had a © Association for European Transport and Contributors 2011 1 domestic air trip rate per capita on 2.27, most European countries had less than one third of this value. Moreover, Williams et al. (2007) shows that Norway has the highest number of commercial airports with short runways (< 1 000 m) in Europe. 1 The state, through the wholly owned company Avinor, owns and operates 46 airports throughout Norway with a total annual traffic of about 40 million passengers (PAX) in 2010 (Avinor, 2011). Avinor organizes the airports in three groups where the main airport of Norway makes the first group, the three other large airports located by the cities Bergen, Stavanger and Trondheim makes the second group and the remaining 42 airports makes the third group as illustrated in Figure 1. For further details regarding the airport network in Norway see e.g. Lian (2010). Figure 1 Norwegian airports owned by Avinor (Source: Avinor) 2.2 Current Airport Charges The airport charges imposed on air traffic are compound of five elements; 2 starting, passenger, security, TNC (Terminal Navigation Charge) and in-flight. Security and TNC are charged according to costs, while in-flight charges are set by Eurocontrol. The two remaining categories, starting charge and passenger charge which is the focus of this study, are set by Avinor according to the directions from the Norwegian Ministry of Transport and © Association for European Transport and Contributors 2011 2 Communication. Avinor also generates revenues indirectly related to air transport from commercial activities such as rent from shops and tax-free sales. Prices for the commercial activities are determined by Avinor. Total revenues are almost evenly distributed between PAX and ATM charges on one hand and commercial activities on the other hand. The basis for this study is the airport charges for 2009 which is the year of reference for all comparisons between new and old charges. Passengers were charged NOK 36 3 and NOK 59 for domestic and international flights, respectively. Air traffic movements were charged NOK 96 per tonne according to the aircrafts’ maximum take-off weight (MTOW). For particularly large aircrafts the charge is reduced to NOK 48 for each tonne exceeding 100. The charges were updated in 2010 to match change in costs and the entire scheme for ATM was revised in 2011. 3. THE MODEL Airport charges are vital for the financing of airport infrastructure and make a considerable part of operating costs for airliners. These charges to finance airport infrastructure should, from a welfare economic point of view, be set to reflect the costs imposed by the activities. 3.1 Previous Costs Studies An important basis for the analysis of airports’ costs is to define which services are provided by an airport and how they can be measured. Common production measures to assess the activity at an airport are the number of passengers (PAX), air traffic movements (ATM), work load units (WLU) and commercial revenues, while the size (or capacity) often is measured by runway length, terminal area (square meters), number of gates, etc (see e.g. Martín and Voltes-Dorta, 2011). One should, however, be aware that the choice of production measure and model formulation will influence the cost estimates. A comparison of the results using different production measures is given by Martín and VoltesDorta (2008) revealing large differences in estimated marginal costs depending on model specification. Aiming to internalize external costs of air transport such as noise, pollution and delays (see e.g. Santos and Robin, 2010) also make estimations of social marginal costs more complicated. The most central production measures when studying airports are PAX and ATM. However, a potential problem for econometric analyses is that these two explanatory factors are highly correlated; when PAX increase the number of ATM will increase to meet the increased demand and vice versa. A way to avoid this problem is to use the above mentioned WLU-measure where passengers for example are equivalent to 100 kg and counting together with the weight of the airplane. This production measure has, however, shown to be imprecise and vague and is rarely used in recent studies. © Association for European Transport and Contributors 2011 3 Marginal costs can be derived using econometric analysis and form the basis for designing charge schemes to finance airport infrastructure. An example of marginal cost estimation in Scandinavia was carried out by Carlsson (2003) using an exponential model with passengers as the only independent variable and explained about 96% of variation in costs between airports. When aiming to meet revenue restrictions the Ramsey-rule has been applied by MartinCejas (1997) and Hakimov and Scholz (2010) to design charge schemes based on marginal cost estimates for Spanish and German airports, respectively. 3.2 The Applied Cost Model An econometric approach using a model with the production measures number of passengers (PAX) and air traffic movements (ATM) as independent variables is applied to study the costs structure at Norwegian airports. Moreover, a dummy variable (INT) is introduced to indicate whether airports have established infrastructure for international flights. The applied cost model is presented in equation (1). (1) where The dependent variable, costs ( ), in (1) is measured in Norwegian kroner (NOK) at the 2009 price level. The accounting figures are reported by Avinor and include all costs at the airport except security which is an outsourced service and covered by a separate charge. Regarding the independent variables, PAX is defined as the number of terminal passengers (sum of arrival and departure and transfer) at both route- and charter flights and ATM is the sum of arrival and departure flights including both route and charter. The dummy variable, INT, is defined as 1 if international PAX at the airport exceeds 5000, else . The limit of 5000 PAX is set in accordance with the airport owner Avinor. Such a lower limit ensures that an airport not really dimensioned for international traffic is not treated as one in the analysis even if international flights should appear on occasion. A-priori assumptions are that all -parameters are positive. The error term has the traditional properties of normal distribution, expected value 0 and non-correlation with the independent variables. The model specification in (1) is linear. Such a model has properties in accordance with reasonable a-priori assumptions regarding the cost structure at Norwegian airports. For example, the linear specification implies that marginal cost for an ATM is independent of PAX at the airport and vice versa. Even if such a specification is less flexible than for example translog, it often provides a good approximation for more advanced models (see e.g. Pels and Rietveld, 2000). Moreover, the results from linear models are easy to interpret. It is clear from (1) that the marginal cost with respect to PAX and ATM are and , respectively. Since (1) do not include capacity measures as independent variables and is estimated using crosssectional data, the marginal cost estimates must be interpreted as long run. 4 © Association for European Transport and Contributors 2011 4 3.3 On Weight based Marginal Costs for ATM There are strong indications that the part of the charge scheme related to ATM should be separated in one part depending on aircraft weight and another part being independent of aircraft weight (see e.g. Graham, 2008). The actual relationship between costs on one hand and ATM and departed tonne on the other hand can be studied further by analyzing empirical data using the specification in equation (2). (2) where The variable WGT is introduced in (2) to represent average airplane weight, measured in MTOW, for an ATM at the airport. The total weight departed at an airport is thereby (ATM × WGT). The exogenous parameter in (2) represents how weight of airplane influence costs and is assumed to be positive. A differentiation of (2) with respect to ATM gives marginal costs meaning that the marginal costs to the airports of a landing can be divided in weight independent marginal costs ( and weight dependent marginal costs . The relationship between marginal costs and WGT is concave, linear or convex for values of less, equal to or higher than 1, respectively. In a study of 161 airports worldwide Martín and Voltes-Dorta (2011) estimated a similar value to 1.1 which indicates increasing unit rates with respect to weight. In contrast, the current charge scheme at Norwegian airports has a decreasing unit rate as accounted for in Section 2.2. Estimations using the Norwegian data set indicate that the statistical properties are about unchanged for values of between 0.8 and 1.2. Hence, since the model is easier to interpret when , this value is applied and implies that marginal costs increase linearly with WGT. The weight based element (ATM WGT) could not be incorporated in (1) due to high multicorrelation. Hence, we have to estimate (2) separately. The fact that model (1) incorporates both PAX and ATM while (2) only includes ATM makes it necessary to adjust the estimates from (2) if they are used in combination with (1). Hence, it can be assumed that the results from (2) is valid in (1) for an average ATM on Norwegian airports which has a weight of 28 tonne. 5 More specifically, the estimated parameter in (2) must be adjusted to match in (1) when airplane weight is 28 tonne. This will be demonstrated in section 4.3. 4. DATA AND ESTIMATION RESULTS 4.1 Data The data set consists of annual observations of production and accounting figures for all 46 airports owned by Avinor for the years 2007, 2008 and 2009. Two airports are omitted from the analysis. First, Oslo airport, Gardermoen (OSL) has been omitted due to its large size compared to the other Norwegian airports. If included OSL accounts for 40% of all airports’ costs and 30% of © Association for European Transport and Contributors 2011 5 ATMs and is, thus, an extreme outlier for all variables. The relevance for the results excluding OSL is handled by studying whether the estimates change if this airport is introduced as a dummy variable. Second, the heliport (purely a landing site for helicopters) at Værøy, (VRY) has been omitted since its cost structure deviates somewhat from regular airports. The observations for all three years are used as a pooled data set to increase the number of observations in a cross-sectional analysis. To our knowledge there have been no major changes in airport operations during these three years that should make pooled data analysis inappropriate. Accounting figures are adjusted to 2009 price level using the consumer price index provided by Statistics Norway. Consequently, the data set contains a total of 132 observations over three years. Descriptive statistics for the pooled data set are presented in Table 1. Table 1 Annual descriptive statistics for the airports (N=132). Variable C PAX ATM INT Average Std.dev. Median Minimum Maximum 40 500 000 42 600 000 20 900 000 10 400 000 197 000 000 452 552 980 148 76 200 5615 4 657 634 9123 14 222 4887 711 70 502 0.26 0.44 0 0 1 Since the average values are significantly higher than the median values all variables in Table 1 are right skewed which is due to the presence of few airports with high traffic and many small airports with low traffic in the data set. The average airport in the data set has annual operating costs of NOK 40.5 million, about 450 000 passengers and 9100 air traffic movements. If OSL is included the average costs would rise to NOK 72.7 million. Table 2 Correlation matrix. Variable Costs (C) Passengers (PAX) Air traffic movements (ATM) International airport (INT) C 1 .96* .95* .76* PAX ATM 1 .98* .67* 1 .65* INT 1 * Significantly correlated at 1% level (2-tailed). The matrix in Table 2 shows that correlations between costs and the independent variables are very high. High correlation is also the case between the independent variables, in particular between PAX and ATM. This is expected from earlier studies of this industry (e.g. Hakimov and Scholz, 2010). 4.2 Estimation Results Estimation results by applying the empirical data in (1) are presented in Table 3. The model explains about 96% of the variation in costs between airports and the F-test indicates good model fit. All estimated parameters have signs © Association for European Transport and Contributors 2011 6 in accordance with the a-priori assumptions and are significantly positive at 1% level, except which is significant at 5% level (2-tailed). Table 3 Estimation results – airport cost model Variable Coefficient Std. dev. Constant 17 230 851 1 166 577 PAX 26.98 4.17 ATM 604 283 INT 21 382 929 2 334 910 N 132 2 R 0.96 F-test 995 t-value 14.8 6.5 2.1 9.2 Further tests of statistical properties indicate near extreme multicollinearity with a mean VIF value of 19.4. This is an expected consequence of the model specification due to the close relationship between the independent variables PAX and ATM. This leads to high standard errors but is not a violation of OSL regression assumptions. The Breusch-Pagan/Cook-Weisberg test and Whites test returned p-values of 0.45 and 0.38, respectively, which fails to reject homoskedasticity at the 5% significance level (e.g. Wooldridge, 2006). A study of the residuals shows mean value about 0 and a slightly skewed and highly peaked distribution. The error term is not significantly correlated to any of the independent variables. Hence, the statistical properties are generally good and indicate that the estimation results from the OLS regression can be trusted. The estimation in Table 3 shows long-run marginal costs for an extra passenger (PAX) of NOK 27 and for an extra air traffic movement (ATM) of NOK 604. Values must be doubled if only departures are charged. Fixed costs are about NOK 17.2 million and additional costs if the airport is prepared for international flights are about NOK 21 million per year. Table 4 Estimation results – weight-based cost model Variable Coefficient Std. dev. Constant 14 985 590 1 206 577 ATM 848 429 ATM × WGT 0.048 0.013 INT 18 701 570 2 908 037 N 132 2 R 0.95 F-test 819 t-value 12.4 2.0 3.6 6.4 Estimation results by using the weight based cost model in (2) are presented in Table 4. The parameters are significantly positive at 5% level or higher and the model generally has good statistical properties. Multicollinearity is present due to the close relationship between ATM and (ATM × WGT). The coefficients in Table 4 shows that for an ATM the weight independent marginal cost is NOK 848 and the weight dependent cost increase by NOK 48 © Association for European Transport and Contributors 2011 7 when airplane weight increases by 1 tonne. This indicates that the ATM charge should not increase proportionally with respect to weight. That is; a weight increase by X% should increase charges by less than X%. For airplanes of 20 tonne and 50 tonne, it follows from Table 4 that the weight dependent part of the ATM marginal costs makes 53% and 74%, respectively 4.3 Marginal Cost Estimations Since (1) includes both PAX and ATM and (2) only includes ATM, a calibration is required if the estimates from the weight dependent model in Table 4 should be used together with the estimates of ATM in Table 3. This enables marginal costs for ATM using weight independent and weight dependent elements and PAX to be applied simultaneously. Let us assume a fixed relative proportion between the values of the weight independent and weight dependent marginal costs. An average aircraft of 28 tonne with marginal costs, according to the -estimate in Table 3, of NOK 604 form the basis for the calculations. An adjustment factor to match Table 4 estimates to the Table 3 estimates can then be calculated according to equation (3). (3) The adjustment factor, , in (3) states that Table 4 estimates should be multiplied by 0.28 if used together with PAX. Hence, weight independent marginal cost for an ATM is NOK 237 (NOK 848 × 0.28) and the increase in marginal cost when the aircraft weight increases by one tonne is NOK 13.40 (NOK 48 × 0.28). These estimates will be combined with the PAX marginal cost amounting to NOK 27. 5. MARGINAL COST BASED CHARGE SCHEMES The Norwegian Ministry of Transport and Communication has stated three main objectives for the revised charges for airports owned by Avinor. First, all requirements of the EU (2009) directive for airport charges must be met. Second, the new charges should to a larger extent than the current ones be based on the principles of welfare economics. Finally, there are budget (revenue) restrictions. Additionally, it has been common practice that charges are equal for all airports throughout the country, but this condition must be relaxed if e.g. Ramsey pricing or peak-load pricing should be implemented. Other considerations are that charges must be perceived as “fair” for both carriers and passengers and meet regional policy objectives. 5.1 Charges Based on Marginal Costs Only Based on the marginal costs estimates for PAX in Table 3 and adjustments according to equation (3) for ATM gives the charges presented in equation (4). The charges are set for departures only, implying that estimated values are multiplied by 2. (4) © Association for European Transport and Contributors 2011 8 It is evident from (4) that marginal cost based airport charges imposed on the air transport companies increase by NOK 54 for each passenger and by a fixed element of NOK 474 and a variable element increasing by NOK 26 per tonne according to the maximum take-off weight (MTOW) for the airplane. A comparison between the marginal cost charges suggested in (4) and current charges shows that, on average for domestic and international flights, ATM charges are reduced by NOK 52 for an average aircraft of 28 tonne and PAX charges are increased by NOK 10. This corresponds to a reduction of 54% for ATM and an increase of 23% for PAX. Consequently, marginal cost pricing implies a transfer in taxation from ATM to PAX. That is; even though both elements should still be taxed, it is indicated that a considerable shift towards charging PAX should be implemented. A consequence of marginal cost pricing is, however, that total revenues are reduced by about NOK 700 million compared to the current charge scheme for Norwegian airports. Several approaches can be chosen to meet a budget, or revenue, restriction. The simplest way is to raise all marginal costs elements by the same factor, relatively spoken, that is sufficiently high to match revenues generated by the current charge scheme. Such an adjustment would raise the airport charges by 57% to NOK 85 for PAX and NOK 748 + NOK 42 × MTOW for ATM. It could, of course, be questioned whether it is reasonable to use the same percentage adjustment factor for all three elements of the airport charges in (4), but we have no indications of the direction of such differentiations of the adjustment factor. Another well recognized approach to meet revenue restrictions is to use the differences in air travelers’ price elasticity throughout the country by the Ramsey-rule. Charges could, for example, be differentiated at the airport level. The diversity in airport location from rural areas to large cities enables a differentiation according to the presence of alternative transport for passengers. The price elasticity will be lower (less price sensitive) if alternative transports are few. Hence, such airports should have a higher raise in marginal costs than airports located in regions with many transport alternatives. Ramsey pricing according to these criteria could, however, be problematic from a regional policy perspective since the group with few alternatives (which would get the highest raise) usually is located in rural areas where the airport is regarded an important mean for continued settlement and further economic development. An example of the implementation of the Ramsey-rule at Norwegian airports according to these criteria is given by Jørgensen et al. (2011). 5.2 Taking into Account the Costs of Raising Public Funds The deficit arising from marginal cost pricing must be financed by the state. Hence, it should be addressed whether the raising of public funds to finance the revenue loss has any welfare economic consequences. The costs for general taxation have been studied empirically and The Norwegian Ministry of Finance (2005) has concluded that an add-on factor of 20% should be used as a rule. © Association for European Transport and Contributors 2011 9 The welfare optimal charges, given that the loss of revenues must be financed by the state, can be derived by maximization of social surplus under budget constraint. When solving the Lagrange function the expression for optimal price, P*, can be rephrased as in equation (5). (5) where In (5) is optimal price, is marginal costs, X is the demand for airport services, is the price elasticity and is the Lagrange multiplier. Since is negative it is required that to ensure that . The factor represents the reduction in social surplus when the requirement for profit is increased by NOK 1. Hence, can be interpreted as the welfare loss by taxation. If then and optimal charge will, according to (5), be equal to marginal cost. A rephrasing of (5) can be made to show more clearly the adjustment factor, F, for marginal costs under revenue restrictions as presented in (6). (6) where , and It is evident from (6) that F increase when λ increase (higher taxation costs) and when is reduced (lower price sensitivity). It can be derived from (6) that the value of F is 1.26, 1.20 and 1.16 for price elasticities of -0.8, -1.0 and 1.2, respectively, given a welfare loss by taxation of . Hence, assuming a price elasticity of -1.0 and The Norwegian Ministry of Finance (2005) recommendations of taxation costs, the optimal charges based on long-run marginal costs and considering cost of raising public funds are NOK 65 for PAX and NOK 569 + NOK 31 MTOW for ATM. 6. CONCLUSIONS AND IMPLICATIONS This paper presents the results from a project initiated by the Norwegian Ministry of Transport and Communication aiming to derive airport charges that are more in line with principles of welfare economics. A multiple regression model is applied to derive marginal costs for passengers (PAX) and air traffic movements (ATM) being the two main production measures at airports. The empirical data consists of accounting and production figures for all 46 Norwegian publicly owned airports for the years 2007 to 2009. When disregarding the social cost of raising public funds, it is well recognized that marginal cost pricing produces the highest social surplus and therefore is desirable from a perspective of welfare economics. Under reasonable assumptions regarding travelers’ price elasticity and using the Ministry’s recommendation for costs of raising public funds, airport charges should be raised by about 20% based on marginal costs when aiming to maximize the airports’ social surplus. If the charges aim to generate the same revenues as the current charge scheme the values should be raised by an even higher factor. The derived values for the three different marginal cost based charge © Association for European Transport and Contributors 2011 10 schemes are presented in Table 5 along with the current charge scheme. For all marginal cost based charge schemes using raised values the adjustment factor is similar for PAX and ATM. This simplification is made because there is no evidence of how the adjustment factor should be differentiated. Table 5 Charge schemes based on long-run marginal costs (MC) and current charges. ATM PAX Fixed MTOW Marginal cost (MC) pricing 54 474 26 MC pricing adjusted for welfare loss 65 569 31 MC pricing adjusted to 2009 revenue 85 748 42 Current charges (2009) * 44 0 96 * Valid for aircrafts with MTOW less than 100 tonne. Two main changes are suggested by the marginal cost based charges compared to the current scheme. First, there should be a shift towards relatively higher charge put on PAX compared to ATM. For example, if revenues should be held at the 2009 level but based on marginal costs the ATM charge is NOK 1924 (748 + 28 × 42) compared to NOK 2688 (28 × 96) based on the current charge scheme for an average departure of 28 tonne. This is in line with IATA (2010) recommendations that, wherever possible and practical, airports should transition to passenger based charges. The benefits are related to improved accountability for passengers and lower risk for airline companies. In isolation, such a change will make a higher proportion of the carriers’ costs variable and, thereby, reduce the cabin factor required to establish new routes. Second, the ATM charge should be divided in two parts of which one element depends on airplane maximum take of weight (MTOW) and another fixed element is independent of flight weight. Such a separation is reasonable since many factors related to serving planes at airports do not vary with MTOW. Even though the data set contains objective information which is considered reliable, there is potential for further improvements in the analysis if a more detailed data set is made available. This particularly regards separating costs related to the inside area (e.g. terminal) and the airside area (e.g. runway system). Such data would enable us to run econometric regressions on inside costs using PAX as independent variable and on airside costs using ATM as independent variable. Analyses would then be more accurate and the problem of multicorrelation would be omitted. © Association for European Transport and Contributors 2011 11 REFERENCES Avinor. (2011) Traffic statistics, http://www.avinor.no/en/avinor/traffic. Carlsson, F. (2003) Airport marginal cost pricing: Discussion and an application to Swedish airports. International Journal of Transport Economics, 30 (3) 283-304. European Union. (2009) Directive 2009/12/EC of the European Parliament and of the Council of 11 March 2009 on airport charges Official Journal of the European Union, 52. Graham, A. (2008) Managing Airports: an international perspective (3rd ed.). Butterworth-Heinemann, Oxford. Hakimov, R., and Scholz, S. (2010). Calculation of Ramsey Prices for German Airports. GAP report, Berlin School of Economics and Law. IATA. (2010) Passenger Based Airport Charges, http://www.iata.org/whatwedo/airport-ans/charges/Documents/Passengerbased-airport-charges.pdf. ICAO. (2009) ICAO’s Policies on Charges for Airports and Air Navigation Services. Doc 9082. Jørgensen, F., Mathisen, T., and Solvoll, G. (2011). Lufthavnavgifter i Norge takstsystemets struktur og betydning for tilbud og etterspørsel. (Airport charges in Norway). SIB report 2/2011, Bodø Graduate School of Business, Norway. In Norwegian. Lian, J. I. (2010) Network dependency and airline competition Consequences for remote areas in Norway. Journal of Air Transport Management, 16 (3) 137-143. Martin-Cejas, R. R. (1997) Airport pricing systems in europe and an application of Ramsey pricing to Spanish airports. Transportation Research Part E: Logistics and Transportation Review, 33 (4) 321-327. Martín, J. C., and Voltes-Dorta, A. (2008) International Airports: Economies of Scale and Marginal Costs. Journal of the Transportation Research Forum, 47 (1) 5-22. Martín, J. C., and Voltes-Dorta, A. (2011) The econometric estimation of airports' cost function. Transportation Research Part B: Methodological, 45 (1) 112-127. Pels, E., and Rietveld, P. (2000) Cost functions in transport. In K. Button & D. A. Hensher (Eds.), Handbook of transport modelling, Vol. 1, 321–333. Pergamon, Amsterdam. Santos, G., and Robin, M. (2010) Determinants of delays at European airports. Transportation Research Part B: Methodological, 44 (3) 392-403. © Association for European Transport and Contributors 2011 12 The Norwegian Ministry of Finance. (2005). Veiledning i samfunnsøkonomiske analyser. (Guide for welfare economic analyses). Oslo. In Norwegian. Walters, A. A. (1965) The long and the short of transport. Bulletin of the Oxford University Institute of Economics and Statistics, 27 (2) 97–101. Williams, G., Fewings, R., and Fuglum, K. (2007) Airport provision and air transport dependence in European countries. Journal of Airport Management, 1 (4) 398-412. Wooldridge, J. M. (2006) Introductory econometrics: a modern approach (3rd ed.). Thomson South-Western, Mason, OH. © Association for European Transport and Contributors 2011 13 NOTES 1 Short Take-Off and Landing (STOL) planes such as Bombardier Dash-8 100 (or DHC-8) operate on local airports with runways as short as 800 meters. Local airports with sufficiently long runways are operated by jet planes. 2 All taxes are charged once per trip. A trip (without transfer) includes two flight movements and visits at terminals both at departure and landing. It is however, not common to charge these services separately for the origin and destination airports. 3 € 1 ≈ NOK 8 4 See e.g. Walters (1965) for a further discussion of the application of marginal cost concepts in transport. 5 Average MTOW is weighted by the traffic amount at the airports and, thereby, calculated by dividing the sum of departed tonne for the whole industry by the total number of departures. The average for 2007, 2008 and 2009 is 28349 kg which is approximated to 28 tonne in the analysis. © Association for European Transport and Contributors 2011 14
© Copyright 2026 Paperzz