Rail cost function analysis has been a popular topic in the (empirical) economics literature over the past decades. Most studies find increasing returns to density for rail companies. The results can, however, be quite diverse. Results for the Dutch National Railway company (NS), for instance, indicate very strong increasing returns to density Andrikopoulos and Loizides, 1998) or decreasing returns to density (Preston, 1994). Using the, to our knowledge, most comprehensive dataset for the NS, this paper estimates a translog variable cost function for the NS. While the returns to density parameter shows increasing returns, like so many other papers, the calculated standard errors shows that the null hypothesis of constant returns may not be rejected.

In this paper an airport and airline choice model, based on a nested multinomial logit model, is developed to investigate both airport competition and airline competition in a metropolitan area with multiple departure airports. The model can be used to analyze the effects of, e.g., an improvement in accessibility of a specific airport in a metropolitan area. It is shown analytically that if the frequency elasticity of demand is smaller than 1, unique airfare-frequency and passenger-charge equilibria exist. Next, symmetric equilibria are derived analytically; their properties are also examined. Finally, asymmetric equilibria are derived numerically, while their properties are discussed as well.

In this paper, we offer a meta-analytical synthesis of recent (simulation) studies on environmental tax reform (ETR). The studies considered here look at both environmental effects (e.g., reduction in CO2 emission) and economic effects (e.g. employment gains) consequent upon such a tax reform. The existing statistical results from the literature mainly suggest that the tax type, the recycling policy and the economic model used in the simulations significantly influence the chance that a 'double dividend' effect can be obtained. These empirical results are, however, not entirely conclusive regarding the question of which combination of policies and models will lead to a higher double dividend. This issue is investigated in our study by a quantitative meta-analytic approach. Our meta-analytic statistical experiment demonstrates that the total effect of a tax-and-recycle policy has a significant influence on the economic variables (second dividend), when employment is used. It is also shown that different definitions of the double dividend contribute in determining the success of ETR, in particular since the effects on GDP are less clear than for employment. These findings should be taken into consideration when deploying an ETR in a policy context, in order to prevent a situation where ETR is rejected or accepted solely due to characteristics of one simulation study rather than through a wide set of results from different studies.