Outcomes of antiretroviral treatment programmes in rural Lesotho: health centres and hospitals compared

Introduction: Lesotho was among the first countries to adopt decentralization of care from hospitals to nurse-led health centres (HCs) to scale up the provision of antiretroviral therapy (ART). We compared outcomes between patients who started ART at HCs and hospitals in two rural catchment areas in Lesotho. Methods: The two catchment areas comprise two hospitals and 12 HCs. Patients ≥16 years starting ART at a hospital or HC between 2008 and 2011 were included. Loss to follow-up (LTFU) was defined as not returning to the facility for ≥180 days after the last visit, no follow-up (no FUP) as not returning after starting ART, and retention in care as alive and on ART at the facility. The data were analysed using logistic regression, competing risk regression and Kaplan-Meier methods. Multivariable analyses were adjusted for sex, age, CD4 cell count, World Health Organization stage, catchment area and type of ART. All analyses were stratified by gender. Results: Of 3747 patients, 2042 (54.5%) started ART at HCs. Both women and men at hospitals had more advanced clinical and immunological stages of disease than those at HCs. Over 5445 patient-years, 420 died and 475 were LTFU. Kaplan-Meier estimates for three-year retention were 68.7 and 69.7% at HCs and hospitals, respectively, among women (p=0.81) and 68.8% at HCs versus 54.7% at hospitals among men (p<0.001). These findings persisted in adjusted analyses, with similar retention at HCs and hospitals among women (odds ratio (OR): 0.89, 95% confidence interval (CI): 0.73-1.09) and higher retention at HCs among men (OR: 1.53, 95% CI: 1.20-1.96). The latter result was mainly driven by a lower proportion of patients LTFU at HCs (OR: 0.68, 95% CI: 0.51-0.93). Conclusions: In rural Lesotho, overall retention in care did not differ significantly between nurse-led HCs and hospitals. However, men seemed to benefit most from starting ART at HCs, as they were more likely to remain in care in these facilities compared to hospitals.

A prehistoric thoroughfare between the Ganges and the Himalayas

The greater Himalayan region, including the Tibetan plateau in the north and the Gangetic plain in the south, served as the principal prehistoric thoroughfare for the peopling of East and Southeast Asia. The descendants of ancient migrants through this region ultimately settled lands as far away as New Zealand, Madagascar and the Americas. Several of the keys to understanding the ethnogenesis of human diversity in Asia include the Father Tongue correlation, possible refugia during the Last Glacial Maximum and the hypothesis that language families may have arisen as the result of demographic bottlenecks in prehistory. Ethnolinguistically informed inferences based on Asian Y chromosomal phylogeography permit a reconstruction of episodes of ethnolinguistic prehistory which lie beyond the linguistic event horizon, i.e. beyond the time depth empirically accessible to historical linguistics. The origins of the language families which make up the hypothetical Uralo-Siberian and East Asian linguistic phyla are argued to have lain in the northeastern corner of the Indian subcontinent. Several other Asian language families are shown to be tied to the subcontinent. The Centripetal Migration model, which assumes that migrations in quest of a better life unfolded in both centrifugal and centripetal directions with respect to technologically more advanced centres of civilisation, is opposed to the Farming Language Dispersal theory, which assumes that all linguistic dispersals were driven by agricultural centrifugal migration.

Bargaining for power and information : an experimental and theoretical analysis of the interaction between institutions, externalities and adverse selection

Bargaining is the building block of many economic interactions, ranging from bilateral to multilateral encounters and from situations in which the actors are individuals to negotiations between firms or countries. In all these settings, economists have been intrigued for a long time by the fact that some projects, trades or agreements are not realized even though they are mutually beneficial. On the one hand, this has been explained by incomplete information. A firm may not be willing to offer a wage that is acceptable to a qualified worker, because it knows that there are also unqualified workers and cannot distinguish between the two types. This phenomenon is known as adverse selection. On the other hand, it has been argued that even with complete information, the presence of externalities may impede efficient outcomes. To see this, consider the example of climate change. If a subset of countries agrees to curb emissions, non-participant regions benefit from the signatories’ efforts without incurring costs. These free riding opportunities give rise to incentives to strategically improve ones bargaining power that work against the formation of a global agreement. This thesis is concerned with extending our understanding of both factors, adverse selection and externalities. The findings are based on empirical evidence from original laboratory experiments as well as game theoretic modeling. On a very general note, it is demonstrated that the institutions through which agents interact matter to a large extent. Insights are provided about which institutions we should expect to perform better than others, at least in terms of aggregate welfare. Chapters 1 and 2 focus on the problem of adverse selection. Effective operation of markets and other institutions often depends on good information transmission properties. In terms of the example introduced above, a firm is only willing to offer high wages if it receives enough positive signals about the worker’s quality during the application and wage bargaining process. In Chapter 1, it will be shown that repeated interaction coupled with time costs facilitates information transmission. By making the wage bargaining process costly for the worker, the firm is able to obtain more accurate information about the worker’s type. The cost could be pure time cost from delaying agreement or cost of effort arising from a multi-step interviewing process. In Chapter 2, I abstract from time cost and show that communication can play a similar role. The simple fact that a worker states to be of high quality may be informative. In Chapter 3, the focus is on a different source of inefficiency. Agents strive for bargaining power and thus may be motivated by incentives that are at odds with the socially efficient outcome. I have already mentioned the example of climate change. Other examples are coalitions within committees that are formed to secure voting power to block outcomes or groups that commit to different technological standards although a single standard would be optimal (e.g. the format war between HD and BlueRay). It will be shown that such inefficiencies are directly linked to the presence of externalities and a certain degree of irreversibility in actions. I now discuss the three articles in more detail. In Chapter 1, Olivier Bochet and I study a simple bilateral bargaining institution that eliminates trade failures arising from incomplete information. In this setting, a buyer makes offers to a seller in order to acquire a good. Whenever an offer is rejected by the seller, the buyer may submit a further offer. Bargaining is costly, because both parties suffer a (small) time cost after any rejection. The difficulties arise, because the good can be of low or high quality and the quality of the good is only known to the seller. Indeed, without the possibility to make repeated offers, it is too risky for the buyer to offer prices that allow for trade of high quality goods. When allowing for repeated offers, however, at equilibrium both types of goods trade with probability one. We provide an experimental test of these predictions. Buyers gather information about sellers using specific price offers and rates of trade are high, much as the model’s qualitative predictions. We also observe a persistent over-delay before trade occurs, and this mitigates efficiency substantially. Possible channels for over-delay are identified in the form of two behavioral assumptions missing from the standard model, loss aversion (buyers) and haggling (sellers), which reconcile the data with the theoretical predictions. Chapter 2 also studies adverse selection, but interaction between buyers and sellers now takes place within a market rather than isolated pairs. Remarkably, in a market it suffices to let agents communicate in a very simple manner to mitigate trade failures. The key insight is that better informed agents (sellers) are willing to truthfully reveal their private information, because by doing so they are able to reduce search frictions and attract more buyers. Behavior observed in the experimental sessions closely follows the theoretical predictions. As a consequence, costless and non-binding communication (cheap talk) significantly raises rates of trade and welfare. Previous experiments have documented that cheap talk alleviates inefficiencies due to asymmetric information. These findings are explained by pro-social preferences and lie aversion. I use appropriate control treatments to show that such consideration play only a minor role in our market. Instead, the experiment highlights the ability to organize markets as a new channel through which communication can facilitate trade in the presence of private information. In Chapter 3, I theoretically explore coalition formation via multilateral bargaining under complete information. The environment studied is extremely rich in the sense that the model allows for all kinds of externalities. This is achieved by using so-called partition functions, which pin down a coalitional worth for each possible coalition in each possible coalition structure. It is found that although binding agreements can be written, efficiency is not guaranteed, because the negotiation process is inherently non-cooperative. The prospects of cooperation are shown to crucially depend on i) the degree to which players can renegotiate and gradually build up agreements and ii) the absence of a certain type of externalities that can loosely be described as incentives to free ride. Moreover, the willingness to concede bargaining power is identified as a novel reason for gradualism. Another key contribution of the study is that it identifies a strong connection between the Core, one of the most important concepts in cooperative game theory, and the set of environments for which efficiency is attained even without renegotiation.

The pragmatics of computer-mediated communication between South African and Mexican drug traffickers

South Africa and Mexico are ripe with drug trafficking. The gangs and syndicates running the drug businesses in these two countries collaborate occasionally. Communication between these international drug business partners takes place on social media. Their main language of communication is English, mixed with some limited use of Spanish and Afrikaans. The key purpose of the interactions between the South African and Mexican parties is the organisation of their business activities. This study aims at examining how the drug traffickers position each other and themselves regarding their common business interest and how their relationship evolves throughout their interactions. Moreover, it is of interest to look at how these people make use of different social media and their affordances. For this a qualitative analysis of the interaction between two drug traffickers (one South African and one Mexican) on Facebook, Threema and PlayStation 4 was performed. Computer-mediated communication between these two main informants was studied at various stages of their relationship. Results show that at first the interaction between the South African and Mexican drug traffickers consists of interpersonal negotiations of power. The high risk of the drug business and gang/syndicate membership paired with intercultural frictions causes the two interlocutors to be extremely cautious and at the same time to mark their position. As their relationship develops and they gain trust in each other a shift to interpersonal negotiations of solidarity takes place. In these discursive practices diverse linguistic strategies are employed for creating relational effects and for positioning the other and the self. The discursive activities of the interactants are also identity practices. Thus, the two drug traffickers construct identities through these social practices, positioning and their interpersonal relationship.