My research comprises the analysis of:
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Price based instruments on technology adoption to reduce nitrogen oxides and carbon dioxide.
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The impact of permanent transport policies (congestion charges and driving restrictions) on vehicle use, gasoline consumption, and air pollution.
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The effect of temporary transport campaigns (car-free days) on congestion and air quality.
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The effect of old bus technology on air pollution.
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Air quality alerts and people's response to strict policy measures.
My work
Publications
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Bonilla, J. A., Aravena, C., & Morales-Betancourt, R. 2023. Assessing Multiple Inequalities and Air Pollution Abatement Policies. Environmental and Resource Economics, 84: 695-727.
Abstract
Addressing inequality is recognized a worldwide development objective. The literature has primarily focused on examining economic or social inequality, but rarely on environmental inequality. Centering the discussion on economic or social factors does not provide a holistic view of inequality because it is multidimensional and several facets may overlap imposing a disproportionate burden on vulnerable communities. This study investigates the magnitude of air quality inequality in conjunction with economic and social inequalities in Bogotá (Colombia). It explores where inequalities overlap and assesses alleviation measures by tackling air pollution. We develop a composite index to estimate performance in socioeconomic and air quality characteristics across the city and evaluate inequality with a variety of measures. Using an atmospheric chemical transport model, we simulate the impact of three air pollution abatement policies: paving roads, industry fuel substitution, and diesel-vehicle renewal on fine particle concentrations, and compute their effect on inequality. Results show that allocation of air quality across Bogotá is highly unequal, exceeding economic or social inequality. Evidence also indicates that economic, social and air quality disparities intersect, displaying the southwest as the most vulnerable zone. Paving roads is found to be the most progressive and cost-effective policy, reducing overall inequality between 11 and 46 percent with net benefits exceeding US$1.4 billion.
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Guzman, L. A., Beltran, C., Bonilla, J. A., & Cardona, S. G. 2021. BRT fare elasticities from smartcard data: Spatial and time-of-the-day differences. Transportation Research Part A: Policy and Practice, 150, 335-348.
Abstract
The changes in public transport ridership can be quantified as fare elasticities that are useful inputs to inform planning and policymaking, particularly for Bus Rapid Transit (BRT) systems in developing city contexts. This research provides new evidence to the limited literature in the Global South about revealed preferences fare elasticity from disaggregated data and improves our knowledge of BRT passengers’ travel behavior providing insights on the important role of achieving an affordable fare. Using a 9-year smartcard data, we show that in a spatially segregated city, such as Bogotá, the BRT fare has differential effects according to the socio-economic characteristics of its users and the time-of-the-day. To estimate the fare elasticity considering the socio-economic heterogeneity of users, we proposed a clustering algorithm based on the station-demand profiles and an indicative average per capita income associated with the station catchment area. The results show significant statistical differences in elasticities between the three identified clusters. The stations located in the urban periphery, associated with low-income areas, show null or low response to the fare changes, as opposed to the stations located on the east edge of the city (wealthiest zones). These findings show that a flat fare in the BRT system has differential fare effects on users, therefore, considering those differences when designing the fare policy scheme would contribute to starting to close accessibility gaps in the city.
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Bonilla, J.; Coria, J.; Sterner, T. 2018. Technical Synergies and Trade-Offs Between Abatement of Global and Local Air Pollution. Environmental and Resource Economics 70(1): 191–221.
Abstract
In this paper, we explore the synergies and tradeoffs between abatement of global and local pollution. We build a unique dataset of Swedish combined heat and power plants with detailed boiler-level data 2001–2009 on not only production and inputs but also on emissions of CO2 and NOx. Both pollutants are regulated by strict policies in Sweden. CO2 is subject to the European Union Emission Trading Scheme and Swedish carbon taxes; NOx—as a precursor of acid rain and eutrophication—is regulated by a heavy fee. Using a quadratic directional output distance function, we characterize changes in technical efficiency as well as patterns of substitutability in response to the policies mentioned. The fact that generating units face a trade-off between the pollutants indicates the need for policy coordination.
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Bonilla, J.; Coria, J.; Mohlin, K.; Sterner, T. 2015. Refunded emission payments and diffusion of NOx abatement technologies in Sweden. Ecological Economics 116, 132–145.
Abstract
This paper studies how different NOx abatement technologies have diffused under the Swedish system of refunded emission payments (REP) and analyzes the determinants of the time to adoption. The policy, under which the charge revenues are refunded back to the regulated firms in proportion to energy output, was explicitly designed to affect investment in NOx-reducing technologies. The main finding is that REP had a significant effect on the adoption of post-combustion technologies. Moreover, we also find some indications that the effects of REP have been enhanced by the existing system of individual emission standards. In particular, the effect of REP speeding up the pace of adoption of post-combustion technologies is considerably larger in those counties where stringent standards are in place.
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Westerlund, J., Urbain, J.-P., Bonilla, J. 2014. Application of air quality combination forecasting to Bogota. Atmospheric Environment 89, 22-28.
Abstract
The bulk of existing work on the statistical forecasting of air quality is based on either neural networks or linear regressions, which are both subject to important drawbacks. In particular, while neural networks are complicated and prone to in-sample overfitting, linear regressions are highly dependent on the specification of the regression function. The present paper shows how combining linear regression forecasts can be used to circumvent all of these problems. The usefulness of the proposed combination approach is verified using both Monte Carlo simulation and an extensive application to air quality in Bogota, one of the largest and most polluted cities in Latin America.
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Bonilla, J. A. 2019. The More Stringent, the Better? Rationing Car Use in Bogota with Moderate and Drastic Restrictions. The World Bank Economic Review 33(2): 516-534.
Abstract
Rationing car use based on license plate number has become a popular policy in several cities around the world to address traffic congestion and air pollution. This paper studies the effects of the moderate and drastic driving restrictions imposed as part of the Pico y Placa program on car use and air pollution in Bogotá. Using data on ambient carbon monoxide, gasoline consumption, and vehicle sales and registrations, no evidence of an improvement in air quality or a reduction in car use is found in either phase of the program. On the contrary, there is some indication that, relative to the moderate phase, gasoline consumption, vehicle ownership, and carbon monoxide in the morning peak tended to increase slightly when drastic restrictions were implemented.
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Coria, J.; Bonilla, J.; Grundström, M.; Pleijel, H. 2015. Air pollution dynamics and the need for temporally differentiated road pricing, Transportation Research Part A: Policy and Practice 75, 178-195.
Abstract
In this paper we investigate the effects of the temporal variation of pollution dispersion, traffic flows and vehicular emissions on pollution concentration and illustrate the need for temporally differentiated road pricing through an application to the case of the congestion charge in Stockholm, Sweden. By accounting explicitly for the role of pollution dispersion on optimal road pricing, we allow for a more comprehensive view of the economy–ecology interactions at stake, showing that price differentiation is an optimal response to the physical environment. Most congestion charges in place incorporate price bands to mitigate congestion. Our analysis indicates that, to ensure compliance with air quality standards, such price variations should also be a response to limited pollution dispersion.
Air quality monitoring station
Working papers
Bogotá in a day with low concentration of PM
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Bonilla, J. and Carriazo, F. 2018. Assessing social experiments using Apps: the case of Car-free days in Bogotá. Documento CEDE 2018-50. Bogota.
Abstract
Nowadays, several Apps record real-time data from social networks that enrich users’ decision making. We argue that these data may also be used to better inform policy makers in the absence of monitoring data or as a complementary tool of measurement systems. This is the case of Waze, an App designed to facilitate access to information on real-time traffic conditions reported by users and based on navigation tools through Global Position System in smartphones. We collect traffic speeds reported by Waze and use air quality measurements from the Air Quality Network in Bogotá to assess the impact of car-free days, a social experiment in Bogotá, aimed at promoting the use of alternative transport modes rather than automobile travel, and temporally addressing congestion and air pollution. Our results suggest that car-free days improve traffic speed in 20% and local air quality, measured by particulate matter, in 2%, compared to classical working days.
Bogotá in a day with increasing concentration of PM
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Bonilla, J. 2018. Should we blame buses? Bus strikes and air quality
Abstract
Buses have been considered generally a fairer, cheaper, greener and healthier mode of suppling transport to citizens than cars. Since a bus may carry much more people than a car in the road, buses might substitute some car trips. Thus, it is reasonable for authorities to design and implement public policies to promote the use of buses and reduce car use. We study the environmental impact of buses in Bogotá using bus strikes in the past eighteen years as a natural experiment. Our results indicate that air quality significantly improves during the strikes. Particulate matter declined around 19% the day when the bus strike was in effect. This impact is ten times greater than the air quality effect of cars reported in a recent study that evaluates car-free days. Our study provides evidence against the argument that buses are green in Bogota.
Work in progress
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Cleaning the air: Good policies against bad air quality? (with Villegas, C., Arango, S. and Orrego, S.)
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How does traffic congestion affect air pollution? A comparative analysis across countries (with Kacker, K., Tan-Soo, J., and Qin, P.).
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Ground-level ozone under traffic disruptions: gasoline and diesel vehicles-free days (with Bento, A.).