conference paper
MS Thesis
This dissertation comprises two essays that study normative environmental policy and the purported side effects of (already enacted) environmental policies. In the first essay, we analyze the management of a stock pollutant in a simplified economy using optimal control. The level of stock pollutant affects utility negatively and it may trigger a catastrophic event when it hits a predetermined threshold, which results in a sudden drop in utility. A numerical illustration for the case of global climate change shows that decision maker can delay the onset of a catastrophe by increasing abatement (by investing into green capital); and by improving the environmental performance of production technology. This delaying effect can be amplified by using both policy instruments in tandem. We also observe that the time to catastrophe slightly increases with a decrease in discounting factor; an increase in the amount of catastrophic damage and a decrease in post-catastrophe capital prices. The time period from 1979 to 2003 saw the emergence of Corporate Average Fuel Economy (CAFE) standards, fluctuating and then stabilizing gasoline prices, and an increased share of light trucks. In the second essay, we analyze the alleged causality of this increased share by the introduction of fuel economy standards. We estimate the market demand for fuel economy of domestic cars and light trucks using a polynomial lag model. The main result of this essay is that the rising share of light trucks in the new domestic vehicle sales can be attributed to the increase in personal incomes during the 25 years considered, aided by the provision of laxer fuel economy standards for light trucks. Moreover, the fuel economy standards did increase the fuel efficiency of domestic vehicles.
working paper
Transit operator absence from work is a costly and pervasive problem within public transport organizations. This paper reviews over forty international studies in order to document significant factors related to this phenomenon. We begin with a brief assessment of the magnitude and costs of operator absence and isolate two major theories which have been proposed to explain operator absence behavior: the income-leisure tradeoff and occupational stress. Case study reports from three U.S. public transport organizations are used to illustrate the range of factors which influence employee absence behavior. We conclude with suggestions for organizational changes which may serve to reduce operator absence and suggestions for further research.
conference paper
conference paper
Ramp metering on freeways is one, among many others, application in which a proportional-integral (PI)-Controller has been successfully used to keep the system at a desired state. However, the design becomes challenging if the system presents a dead time restricting the stability region and affecting performance. The cause of the dead time is the distance between the on-ramp and the lane drop. A change in the control action affects the system after the time taken to vehicles travel this distance. There are a vast literature in the control theory addressing the effects of dead time and techniques to overcome it, but it is not to ramp metering control. In this study, a dynamic model of the system is presented along with ALINEA, an established Ramp Metering control algorithm based on a PI-Controller. The authors show that by incorporating a Smith Predictor into ALINEA, the stability region becomes larger, insensitive to the dead time, and can be found analytically. Numerical experiments confirm the analysis and that the proposed controller still presents a larger stability region even when there are modeling errors, allowing a faster response to disturbance.
policy brief
California set ambitious goals for decarbonizing the transportation sector, including reducing the amount of per capita vehicle travel. This may mean shifting more travel to other modes of travel, such as ride-hailing (i.e., on-demand services such as Uber, Lyft, and taxis) and public transit. To better understand different types of non-automobile travelers, the research team examined the connections between the tour-based travel patterns of public transit and ride-hailing users and their household activities. The team’s analysis used an activity-based approach that considers daily travel patterns using tours and activity patterns as basic units of analysis. The researchers identified different subgroups or “classes” of riders based on the type of trips taken and modes used and then analyzed the socio-demographic composition of each class. All tours considered in the team’s study start and end at home, with at least one trip by ride-hail or transit. Additionally, tours were classified as work or non-work trips, and complex or simple trips.
published journal article |
Oct 2021
published journal article |
Apr 2023
published journal article
Discretionary grant programs have been popular with state legislatures as a mechanism for extending the benefits of transit programs to small cities and rural areas as well as for stimulating innovations in urban areas. This article analyzes state discretionary grant transit programs in California and Minnesota by using the criterion of effective administration. The purpose is to develop a framework for understanding administrative problems that result when state discretionary transit programs do not have adequate objectives. Without explicit objectives, selection, monitoring, evaluation, and overall management are weak. Project performance is reduced and scarce public funds are wasted. Recommendations include the following: (a) legislatures should make explicit the mission and goals of discretionary programs, (b) administrative agencies should define measurable objectives and administrative guidelines, and (c) local grant recipients should be granted funds only after specific objectives and performance standards have been presented.
published journal article
The fiscal decentralization impulse now sweeping the world often leads to partial decentralization, where subnational governments are funded by central transfers. rather than leading to full local autonomy. Despite the practical important of this arrangement, the literature contains no economic analysis of a partial decentralization regime in a Tiebout-style model. This paper provides such an analysis, relying on the key assumption that public-good provision requires effort on the part of government officials. By choosing different degrees of effort, localities can then provide different public-good levels even when a fixed, common transfer constrains them to spend the same amount. A number of useful results are derived. (C) 2008 Elsevier B.V. All rights reserved.
research report
conference paper