expansion of criminality associated with the greater mobility of criminals as a boomerang effect of Bogotá’s BRT (Olarte Bacares 2014).

In addition, recent literature has begun to question the welfare impact of BRT systems, particularly through the effect of the systems on property values and urban land development. Various studies have associated the implementation of BRT systems with land value uplift (see below). Yet, as Stokenberga (2014) points out, more rigorous assessment is needed to understand the impact of the systems on land use and prices. For example, the majority of studies, which are predominantly crosssectional, look at land prices rather than at changes in land prices. Stokenberga also highlights the importance of understanding whether BRT systems expand the accessibility of households previously living along the corridors or whether a price rise leads to displaced population segments. Indeed, as discussed in the next sections, the present paper finds evidence of composition effects that suggest that a gentrification process is occurring.

Some of the main research on BRT systems concentrates on impacts on housing markets. This constitutes the area of research that has received by far the most attention. Several studies have looked at the impact of the TransMilenio BRT system on the housing market in Bogotá. Thus, using spatial hedonic price functions, the cross-sectional analysis of Rodríguez and Targa (2004) suggests that land values decline as the walking distance to a BRT station becomes greater. The analysis of Munoz-Raskin (2010) on the impact of TransMilenio, also based on a hedonic analysis, uses Department of Housing Control data for 2000–04. His results indicate that property values are higher if properties are close to a feeder line. Furthermore, the prices of middle-income properties tend to be higher, the closer they are to the system, while the opposite is true of low-income housing. Rodríguez and Mojica (2009) use data before and after the expansion of the system to examine whether prices change. Their results suggest that values increased in locations already served by the system, while, in areas that previously did not have a BRT station, but that are now served by the extension, land values did not rise. Bocarejo, Portilla, and Pérez (2013) find that, in Bogotá, areas served by the BRT, particularly peripheral areas that have feeder bus routes, exhibit higher growth rates. Using a difference in differences methodology, they conclude that the BRT has contributed to densification. More recently, Rodríguez, Vergel-Tovara, and Camargo (2016) examine the impacts of BRT systems on the land market in Bogotá and Quito by comparing treatment and control corridors based on 10 years of data. Using a quasi-experimental research design, they consider outcomes such as changes in the use of land, property prices, and the built area added per year. Their results show mixed impacts in both cities. Overall, the pace of land development appears to have risen in areas with BRT stops relative to control areas, although market conditions and other factors also play a role. Comparing the results of propensity score matching and spatial hedonic pricing models, Perdomo Calvo (2011) finds that the average price of residential property associated with proximity to a TransMilenio station rose by US$59 using the former and US$50 with the latter method. Similarly, Perdomo Calvo (2017) uses an unbiased specification based on geographical information systems and various econometric techniques to estimate the impact of BRT systems in Barranquilla and Bogotá. Based on pooling cross-sections across time, structural change over time (2006, 2008, and 2011), hedonic price models, Box-Cox 5