EVALUATING THE COMPETITION EFFECTS OF UBER’S ENTRY INTO THE BRAZILIAN INCUMBENT CAB-HAILING APP SEGMENT

2018 ◽  
Vol 14 (4) ◽  
pp. 608-637
Author(s):  
Guilherme Mendes Resende ◽  
Ricardo Carvalho de Andrade Lima
Keyword(s):  
Panel Data ◽  
Spatial Heterogeneity ◽  
Competitive Environment ◽  
Disruptive Effect ◽  
The South ◽  
Difference In Differences ◽  
Data Set ◽  
The North ◽  
Competition Effects

Abstract This paper assesses the competition effects of Uber’s entry into the incumbent cab-hailing app segment in Brazil. Using a monthly panel data set (from 2014 to 2016) covering the Brazilian municipalities and a difference-in-differences estimator, we show that Uber’s entry into the market resulted in an average reduction of 56.8 percent in the number of rides from cab-hailing apps in the cities where the platform operates. The magnitude of this effect suggests that Uber has had a clearly disruptive effect on the incumbent sector. We also found significant spatial heterogeneity in the competition effects of the platform when comparing the markets of the capitals of the North and Northeast regions (where Uber entered late) with the capitals of the South, Southeast, and Central West regions (where Uber entered early). Only in the second group of municipalities, we found that Uber’s entry caused a reduction in taxi fares (reduction of 12.1 percent). This indicates that the cab-hailing app sector reacted to Uber’s entry by offering discounts in fares after a longer period of exposure to a competitive environment.

scholarly journals Regional differences in the evolution of the merger of /ʃ/ and /ç/ in Luxembourgish

2021 ◽  
pp. 1-18
Author(s):  
François Conrad
Keyword(s):  
Language Contact ◽  
Sound Change ◽  
Young Generation ◽  
The South ◽  
Data Set ◽  
West Germanic ◽  
The North ◽  
Minimal Pairs ◽  
Old Men ◽  
Middle Generation

The merger of post-alveolar /ʃ/ and palatal /ç/ into alveolopalatal /ɕ/ has recently gained growing interest in sociophonetic research, especially in the Middle German dialect area. In Luxembourgish, a Continental West Germanic language, the sound change has been linked to age differences, while its origins remain unclear. Two studies with a regional focus are presented in this paper. The first study examines the merger in the Centre and the South of Luxembourg. The acoustic examination of both the spectral peak and the centre of gravity of a spoken data set of five minimal pairs embedded in read and orally translated sentences from 48 speakers (three generations (old generation, 65–91 years; middle generation, 40–64 years; young generation, 20–39 years; each generation, n = 16), men and women) reveals interesting results related to their regional background. In the old generation, the merger is further advanced in the speech of old men from the former mining region in the South compared to their peers in the Centre, the former leading this sound change. On the other hand, young speakers in both regions produce only alveolopalatal /ɕ/, the merger being complete in this generation. The second study presents exploratory data from the East and the North of the country. The analysis of this smaller sample (n = 6 speakers) reveals patterns similar to the central region. Pointing to language contact with Romance in the South as cradle and/or catalyser of the merger, these results not only give further clues as to the development in Luxembourg, but also add to a deeper understanding of sound changes in process in complex sibilant systems.

Authoritarian survival strategies and elite churn: The case of North Korea

2020 ◽  
Vol 23 (2) ◽  
pp. 160-176
Author(s):  
John Ishiyama ◽  
Taekbin Kim
Keyword(s):  
Panel Data ◽  
North Korea ◽  
Survival Strategies ◽  
Leadership Characteristics ◽  
Structural Factors ◽  
Data Set ◽  
The Past ◽  
The North ◽  
Authoritarian Survival ◽  
Scholarly Attention

How do autocrats interact with authoritarian elites? This is a question that has gained increasing scholarly attention over the past decade. In this article, using the case of North Korea we develop a set of theoretical expectations for “elite churn” or changes in the composition of the elite (either in terms of promotions, demotions, or new entrants) resulting from moving around elites from office to office (or “elite shuffle”) and bringing in new elites. We test a number of theoretical expectations derived from the existing literature on elite management in autocracies and then examine these expectations using a panel data set of 351 members of the North Korean elite from 1948–2017. Taking into account leadership characteristics, threats to the regime (both internal and external), external opportunities, and structural factors, we find that the explanation for elite churn in North Korea is very leader specific, and is much more pronounced under Kim Jong Un than his predecessors. This suggests that Kim Jong Un’s position was much more tenuous than his father’s and grandfather’s and likely continues to be so.

Racial Redistricting and African-American Representation: A Critique of “Do Majority-Minority Districts Maximize Substantive Black Representation in Congress?”

1999 ◽  
Vol 93 (1) ◽  
pp. 183-186 ◽  
Author(s):  
David Lublin
Keyword(s):  
African American ◽  
African Americans ◽  
Racial Composition ◽  
The South ◽  
Substantive Representation ◽  
Data Set ◽  
Black Representation ◽  
The North ◽  
Methodological Errors ◽  
The U.S

Contrary to Cameron, Epstein, and O'Halloran's article (1996), (1) racial redistricting remains vital to the election of African Americans to the U.S. House, and (2) the tradeoff between black descriptive and substantive representation is actually greater in the South than in the North. Substantive and methodological errors explain why they arrived at their findings. Specifically, their analysis ignores the effect of the presence of Latinos on the election of African Americans. Ironically, due to the very policy assessed in the article, Cameron, Epstein, and O'Halloran's data set does not allow them to examine the link between the racial composition of a district and the ideology of its representative. In addition, they do not consider that racial redistricting not only changes the aggregation of seats into votes but also indirectly boosts the Republican share of votes and seats.

A nonpartisan legislative chamber: The influence of the Canadian Senate

2020 ◽  
pp. 135406882091134
Author(s):  
Aengus Bridgman
Keyword(s):  
Panel Data ◽  
Legislative Process ◽  
Difference In Differences ◽  
Data Set ◽  
Party Discipline ◽  
Extant Literature ◽  
Members Of Parliament ◽  
Legislative Influence

Measuring relative legislative influence is notoriously difficult, particularly in bicameral systems where two chambers have similar formal powers. Recent changes to the Canadian legislature offer a unique opportunity to understand how an upper house liberated from party constraints impacts that houses’ legislative influence. I leverage an original panel data set matching lobbyist activity to parliamentarian characteristics and responsibilities and, using a difference-in-differences design, compare Members of Parliament to Senators, both independent and partisan. I find that independent Senators receive disproportionately more attention from lobbyists both after the changes and as the independent composition of the Senate grows. This article offers a time-variant measure by which perceived influence can be evaluated and contributes to the extant literature on intercameral relationships, partisanship, the legislative process, and party discipline and cohesion.

scholarly journals Heterogeneity in a communal cattle-farming system in a zone endemic for foot and mouth disease in South Africa

2016 ◽  
Vol 11 (2) ◽  
Author(s):  
Ockert Louis Van Schalkwyk ◽  
Eva M. De Clercq ◽  
Claudia De Pus ◽  
Guy Hendrickx ◽  
Peter Van den Bossche ◽  
...  
Keyword(s):  
South Africa ◽  
Spatial Heterogeneity ◽  
Disease Control ◽  
Temporal Dynamics ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
The South ◽  
Control Zone ◽  
The North ◽  
Foot And Mouth

In South Africa, communal livestock farming is predominant in the foot and mouth disease control zone adjacent to the Greater Kruger National Park (KNP), where infected African buffaloes are common. During routine veterinary inspections of cattle in this area, a large amount of production and demographic parameters were being recorded. These data were collated for a five-year period (2003-2007) in three study sites to better understand the temporal dynamics and spatial heterogeneity in this system. A decreasing gradient from South to North with respect to both human and cattle population densities was observed. Rainfall and human population density alone could explain 71% of the variation in cattle density. Northern and central sites showed an overall decrease in total cattle numbers (15.1 and 2.9%, respectively), whereas a 28.6% increase was recorded in the South. The number of cattle owners in relation to cattle numbers remained stable during the study period. Only 4.0% of households in the South own cattle, compared to 13.7 and 12.7% in the North and Centre. The overall annual calving rate was 23.8%. Annual mortality rates ranged from 2.4 to 3.2%. Low calf mortality (2.1%) was recorded in the North compared to the South (11.6%). Annual off-take in the form of slaughter averaged 0.2, 11.7, and 11.0% in the North, Central and South sites, respectively. These figures provide valuable baseline data and demonstrate considerable spatial heterogeneity in cattle demography and production at this wildlife-livestock interface, which should be taken into consideration when performing disease risk assessments or designing disease control systems.

scholarly journals Integrated geophysical investigations of deeper stratigraphy of the Irish Rockall Basin

2021 ◽  
Author(s):  
Gaurav Tomar ◽  
Srikumar Roy ◽  
Christopher J. Bean ◽  
Satish C. Singh ◽  
Brian O'Reilly ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Sedimentary Basins ◽  
Moho Depth ◽  
The South ◽  
Data Set ◽  
Late Mesozoic ◽  
The North ◽  
Stretching Factor ◽  
The Uk ◽  
Early Cenozoic

<p>The Rockall Trough is an elongate bathymetric depression trending NNE-SSW. It is approximately 1200 km long and up to 300 km wide, extending over the UK and Irish continental margins. The trough is underlain by the Rockall Basin, which forms part of a chain of late Paleozoic-Cenozoic sedimentary basins. The Irish Rockall Basin is vastly unexplored as compared to the UK sector, where extensive flood basalt lava flows, sill complexes and volcanic centers of Late Cretaceous-to-Early Eocene age have been described, which belong to the North Atlantic Igneous Province (NAIP) (Archer et al., 2005). An integrated study of seismic, gravity and magnetic methods elucidates the deeper stratigraphy of the Irish Rockall Basin. More than 10 km of sediments is present in the central part of the basin. We perform first arrival travel time tomography on a downward continued data set of three seismic profiles to model the velocity of the sedimentary structures down to 6 km depth. To better understand the deep structure of the basin we need to estimate the Moho depth from constrained gravity modelling. The modelling results indicate that the Moho depth varies from 12 km to 20 km depth beneath ~10 km thick sediments in the basin. This allows us to measure the crustal stretching factor β. The minimum stretching factor in the basin varies between ~7 in the north to ~6.5 in the south. These values are within the range needed for mantle serpentinisation (O'Reilly et al., 1996; Perez-Gussinye and Reston, 2001). Furthermore, we observe four volcanic ridges in the south part of the basin, which are ~20 km wide and ~ 3 km thick, possibly comprising the Barra Volcanic Ridge System (BVRS) (Scrutton and Bentley, 1988). Results indicate several failed rifting attempts times in late Mesozoic/early Cenozoic times, generating significant basic volcanism, associated with the NAIP. We resolve new volcanic ridges (of late Mesozoic/early Cenozoic age) in the southern part of the Rockall Basin, like many other volcanic ridges/centres observed in other parts of the basin, with correlatable magnetic and gravity anomalies. These may be of late Cretaceous age similar to those found on the conjugate Canadian margin.</p>

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

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