Nous prenons l’approche d’annonce des salaires avec la recherche d’emploi à étudier trois problèmes dans le marché du travail. Le premier problème concerne l’arrêt de travail prématuré des travailleurs. Tel arrêt de travail prématuré crée des risques de chiffre d’affaires pour les entreprises, donc les entreprises veulent proposer des profils de salaire pour minimiser ces risques. Dans ce problème, l’asymétrie de l’information joue un rôle important. Nous adoptons une approche du mécanisme design et considérons les différents timings auxquels l’information privée est réalisée. Dans un papier de suivi, nous proposons une politique d’Age spécifique par laquelle cette inefficacité peut être atténuée, et étudions son implication sur le bien-être et la production globale. Dans le deuxième problème, nous revisitons l’analyse du bien-être de l’impact de la discrimination sur le choix des compétences sous une norme d’embauche multidimensionnelle le long des caractéristiques qui sont soit liées à la productivité soit indépendantes de la productivité. Nous montrons comment l’investissement de compétences stratégique entre le groupe favorise et discrimine se pose. Nous comparons également deux mécanismes de détermination des salaires (salaire annoncé et négocié) pour vérifier la robustesse de résultats. Dans le troisième problème, nous considérons dans quelle mesure l’allocation de chômage et le salaire minimum peuvent corriger les répartitions inefficaces découlant du pouvoir de marche des firmes. Notre contexte concerne les petits marchés ou le ratio travailleurs/firmes ne soit pas grand. L’imperfection de marche vient du fait qu’au marché du travail à petite échelle les firmes paient un niveau de salaire moins que le niveau compétitif. Nous procédons à partir d’un point de vue d’organisation industrielle, et proposons en se concentrant sur la mauvaise répartition d’emploi et de surplus lors de l’analyse de l’efficacité de l’instrument de la politique. / We take the wage posting approach with search friction to study three issues in labor market. The first issue concerns the premature quitting of workers. Our framework is suitable for contexts such as disability shock, retirement, maternity leaves etc. Such premature quitting creates turnover risks for firms, hence the firms propose wage profiles to minimize or avoid it. In this issue, the asymmetric information plays an important role. We adopt an approach of mechanism design and consider different timings at which the private information is realized. In a follow-up paper, we propose an age-directed policy by which this inefficiency can be alleviated and study its implication on welfare and aggregate output. In the second issue, we revisit welfare analysis of impact of discrimination on skill choice under a multi-dimensional hiring norm along both productivity-related and -unrelated characteristics. We show how strategic skill investment between favored and discriminated group arise. We compare also two wage determination mechanisms (posted and bargained wage). In the third issue, we consider to which extent can the roles of unemployment benefit and minimum wage correct inefficient allocations arising from firms’ market power. Our context concerns small markets where the workers/firms ratio is not large. The market imperfection comes from the fact that in such a small market firms pay less than competitive level of wages. We proceed from an industrial organizational perspective and suggest focusing on both misallocation of labor and surplus when analyzing the effectiveness of the policy instrument.

Text in Afrikaans / Summaries in English and Afrikaans / The orthodox school's explanation for wage differentials, unemployment and labour market discrimination and the policy measures which they proposed did not offer workable solutions to the problems of the day. During the late 1960s and early 1970s a group of American labour economists conducted field studies in American urban ghettos which resulted in the formulation of the dual labour market theory. In contrast with the orthodox approach, which emphasises free market forces and investment in human capital, the dual labour market theory focuses on the dual structure of the labour market. The labour market is divided between a primary (high-wage) and a secondary (low-wage) sector, with little or no mobility between the sectors. An oversupply of labour in the secondary sector and unemployment are the results. These labour market phenomena and dualism also characterise the South African labour market and should be taken into account when policy measures are formulated. / Loonverskille, werkloosheid en arbeidsmarkdiskriminasie is algemene verskynsels in arbeids· markte wereldwyd. Die ortodokse denkskool se verklaring vir die verskynsels en die beleidsmaatreels wat bulle voorste~ het met verloop van tyd ontevredenheid ontketen omdat dit geen werkbare oplossing vir die probleme van die dag kon hied nie. Gedurende die laat ·1960s en vroee 1970s het 'n groep Arnerikaanse arbeidsekonome verskeie veldstudies in verskillende Arneri· kaanse stedelike ghetto's geloods op soek na 'n meer aanvaarbare verklaring vir hierdie verskyn· sels. Uit hierdie veldstudies is die dualistiese arbeidsmarkteorie geformuleer. In teenstelling met die ortodokse benadering, wat Idem le op die werking van vrye markkragte en investering in menslike kapitaal, benadruk die dualistiese arbeidsmarkteorie die tweeledige struktuur van die arbeidsmark. Die arbeidsmark is verdeel tusssen 'n primere (hoogbesoldigde) en sekondere (laagbesoldigde) sektor, met min of geen mobiliteit tussen die sektore nie. Werkers se toegang tot die primere sektor word beperk, met 'n ooraanbod van arbeid in die sekondere sektor en werkloosheid as die gevolg. Hierdie arbeidsmarkverskynsels en dualisme is ook kenmerkend van die Suid·Afrikaanse arbeidsmark en beleidsmaatreels moet daarmee rekening hou / Economics and Management Sciences / M. Comm. (Economy)

My research seeks to understand the behaviour of workers and firms and how their decisions affect labour market outcomes. My PhD dissertation consists of three separate Chapters that use detailed historical, census and administrative data to gain insights into the mechanisms at play when incentives for production and location decisions change. Chapter 1 asks whether financial incentives can induce inventors to innovate more. I exploit a large reduction in the patent fee in the United Kingdom in 1884 to distinguish between its effect on increased efforts to invent, and a decrease in patent quality due to a lower quality threshold. For this analysis I create a detailed new dataset of 54,000 British inventors with renewal information for each patent. In the longer run high-quality patenting increases by over 100 percent, and the share of new patents due to greater effort accounts for three quarters of the pre-reform share of high-quality patents. To test for the presence of credit constraints I generate two wealth proxies from inventor names and addresses, and find a larger innovation response for inventors with lower wealth. These results indicate efficiency gains from decreasing the cost of inventing and in addition, from relaxing credit constraints. In Chapter 2 we assess the effects of changes in ethnic neighbourhood composition in England and Wales. A change in social housing allocations in the 1990s serves as instrument for changes in the local ethnic composition. For the analysis we create a dataset of highly disaggregated census geographies for 1991-2011. The results imply that an exogenous increase in social housing minority share by 10 percentage points raises the minority share in private housing by 1.2 percentage points initially. This sorting effect is larger for privately rented than for privately owned housing. We further show that an increase in the minority share leads to higher local population growth and a small decrease in house prices in the longer run. Chapter 3 proposes a new approach for analysing responses to comprehensive labour market reforms. Using detailed micro data we evaluate the German Hartz reforms that aimed at reducing unemployment. The timing of the reforms affects the model parameters, which are estimated using matched data on 430,000 workers in 340,000 firms. Contrary to previous findings, our analysis shows that the reforms marginally reduced unemployment at the cost of a pronounced decline in wages. Low-skilled workers suffered the largest wage losses. Furthermore, we decompose the contribution of each reform wave on employment and wages, and document a structural shift in the factors that govern overall wage dispersion.

This thesis examines the theoretical premises of and ways that macro deliberative approaches to decision making function in application to specific instances of science and technology governance. Macro-level deliberations constitute complex, extended, distributed decision making processes, in contrast to individual micro deliberation exercises undertaken in particular settings. Macro deliberations employ the mechanism of ‘division of labour' in terms of actors, tasks and methods in order to secure the two essential qualities of ‘inclusiveness' and ‘deliberativeness' – thus resolving the inherent tension between number of participants and deep discussion. Accordingly, the thesis focuses on the ways in which this paradoxical mechanism of ‘inclusion by division' functions in macro deliberations. An interrogation of two UK nationwide public deliberation cases – GM Dialogue (on GM crops) and the CoRWM process (on radioactive waste) – sheds light on the significant role of reflexivity in such macro deliberative approaches to decision making. The thesis adopts a triangulated approach towards both documents and interviews employing contending representations to cross-check the one with the other. In considering the ways in which reflexivity constitutes a critical quality of the process and outcome of division of labour in macro deliberations, the thesis argues that the notion of reflexivity is central to explaining how macro deliberation functions: The reflective and self-contingent feature of reflexivity enables participants to explore diverse rationales on division of labour through continuous generation of new rationales; this recursive self-reconfiguration process of rationales on division of labour entails an evolutionary development of division of labour. As division of labour is played out not in a static, exogenous fashion, but through a dynamic, endogenous construction process, reflexivity in real-world macro deliberations illuminates some significant contrasts in the ways that ‘deliberation' and ‘inclusion' take place to those characterised in theory. Indeed, deliberation emerges in practice as more than just open rational dialogue. In order to understand this more fully, it must be seen in terms of diversity of material, social and political interactions, and relationships – referred to here as ‘discursive relations'. In reality, then, inclusion occurs in more emergent ways than intended by design, rather, unfolding as participants engage with each other. In this way, actors' divergent views are cross-reflected and mutually influence each other, not through theoretically-envisaged top-down aggregation but via a kind of endogenous ‘fermentation' process. In this way, reflexivity actually makes macro public deliberation a more effectively inclusive and deliberative decision making process. In short, recognition of this inherent reflexivity in macro deliberations offers practically to aid improved understanding of the complex process of engagement in science and technology governance. It suggests that we would benefit from shifting our attention somewhat away from the direct provision of strictly prescriptive design protocols towards the construction of better general environments for facilitating more reflexivity, which should enable actors to shape their own reflexive deliberation. Then let them brew!

This thesis is about imperfections in urban labour markets of three developing countries. I study how physical living conditions place constraints on labour force participation, and increase risks associated with unemployment. In Chapter One I test for the impact of high search costs on labour market outcomes of job seekers. I use a randomized trial of transport subsidies among youth living far away from the centre of the city in Addis Ababa, Ethiopia. Lowering transport costs increases the intensity of job search and leads to better employment outcomes. Weekly phone call data shows that treatment works to stop job search activity from declining over time. I show that the results are consistent with a dynamic model of job search with cash constraints and monetary search costs. Income from temporary work is used to smooth consumption and pay for the costs of search. I find that subsidies reduce participation in temporary work. Chapter Two looks at the links between poor housing conditions in slums and market labour supply. I test for the effect of free government housing in South Africa on households, using four waves of panel data and a natural experiment due to the allocation of new housing according to proximity from housing projects. I then use planned but cancelled projects to control for non-random selection of housing project sites. I find that government housing leads to large increases in household incomes from wage work, and increases in the labour supply of female household members. I argue that these results are due to reduced burdens of work in the home of improved housing, especially for women. In Chapter Three we look at how labour markets respond to large but temporary economic shocks caused by typhoons in the Philippines. We use quarterly aggregate, repeated-cross sectional and panel data to demonstrate robust evidence of downward wage flexibility. Lay-offs do not occur when storms hits, but hours per worker fall. We explain these results with a model of implicit contracts under which risk is shared between workers and firms through wage cuts, but workers are insured against lay-offs so that adjustments in labour demand occur through reductions in hours per worker. Our results are particularly strong for workers in long term contractual relationships in the private sector.

Text in Afrikaans / Summaries in English and Afrikaans / The orthodox school's explanation for wage differentials, unemployment and labour market discrimination and the policy measures which they proposed did not offer workable solutions to the problems of the day. During the late 1960s and early 1970s a group of American labour economists conducted field studies in American urban ghettos which resulted in the formulation of the dual labour market theory. In contrast with the orthodox approach, which emphasises free market forces and investment in human capital, the dual labour market theory focuses on the dual structure of the labour market. The labour market is divided between a primary (high-wage) and a secondary (low-wage) sector, with little or no mobility between the sectors. An oversupply of labour in the secondary sector and unemployment are the results. These labour market phenomena and dualism also characterise the South African labour market and should be taken into account when policy measures are formulated. / Loonverskille, werkloosheid en arbeidsmarkdiskriminasie is algemene verskynsels in arbeids· markte wereldwyd. Die ortodokse denkskool se verklaring vir die verskynsels en die beleidsmaatreels wat bulle voorste~ het met verloop van tyd ontevredenheid ontketen omdat dit geen werkbare oplossing vir die probleme van die dag kon hied nie. Gedurende die laat ·1960s en vroee 1970s het 'n groep Arnerikaanse arbeidsekonome verskeie veldstudies in verskillende Arneri· kaanse stedelike ghetto's geloods op soek na 'n meer aanvaarbare verklaring vir hierdie verskyn· sels. Uit hierdie veldstudies is die dualistiese arbeidsmarkteorie geformuleer. In teenstelling met die ortodokse benadering, wat Idem le op die werking van vrye markkragte en investering in menslike kapitaal, benadruk die dualistiese arbeidsmarkteorie die tweeledige struktuur van die arbeidsmark. Die arbeidsmark is verdeel tusssen 'n primere (hoogbesoldigde) en sekondere (laagbesoldigde) sektor, met min of geen mobiliteit tussen die sektore nie. Werkers se toegang tot die primere sektor word beperk, met 'n ooraanbod van arbeid in die sekondere sektor en werkloosheid as die gevolg. Hierdie arbeidsmarkverskynsels en dualisme is ook kenmerkend van die Suid·Afrikaanse arbeidsmark en beleidsmaatreels moet daarmee rekening hou / Economics and Management Sciences / M. Comm. (Economy)

Cette thèse de doctorat porte sur la dynamique de l’emploi dans les entreprises et sur la relation entre la dynamique de l’emploi et l’innovation, avec une attention particulière portée sur les entreprises nouvellement créées. Cette thèse conceptualise théoriquement et analyse empiriquement les différents aspects de l’interaction complexe entre le changement technologique et la dynamique de l’emploi, en se concentrant sur les effets hétérogènes des différents types d’innovation sur la croissance de l’emploi. Compte tenu le rôle primordial joué par les nouvelles et jeunes entreprises dans le processus de destruction créatrice et leur apport à la création globale de l’emploi, cette thèse fournit une caractérisation de la contribution nette d’emplois des nouvelles entreprises dans un nombre important de pays, en utilisant des données micro-agrégées issues d’une nouvelle base de données. En outre, elle analyse comment un certain nombre de caractéristiques institutionnelles affectent la création nette d’emplois dans les start-ups, en se concentrant sur les effets hétérogènes des politiques sur les nouvelles entreprises et les entreprises déjà existantes. Cette thèse étudie enfin une caractéristique particulière des lois de distribution des taux de croissance de l’emploi, c’est-à-dire la volatilité de la croissance de l’emploi, que non seulement se révèle être une médiation cruciale des effets des politiques sur la création nette d’emplois, mais a aussi d’importantes implications à la fois micro- et macroéconomiques. / This doctoral thesis focuses on employment dynamics in firms, and on the relationship between employment dynamics and innovation, with a particular focus on the entry process. It conceptualizes theoretically and analyses empirically different aspects of the complex interaction between technical change and employment dynamics, focusing on the heterogeneous effects of different types of innovation on employment growth. In the light of the prominent role of newly-born firms in shaping the creative destruction process and contributing to overall job creation, this thesis provides a characterization of the net job contribution by surviving entrants across a significant number of countries. Using newly collected representative micro-aggregated data, it further analyses whether and how a number of institutional characteristics affect start-ups’ net job creation, focusing on the heterogeneous effects of policies on entrants and incumbents. This thesis finally characterizes a particular feature of the employment growth distributions – employment growth volatility – that not only proves to be crucially mediating the effects of policies on entrants’ net job creation, but also has important micro and macroeconomic implications.

Cette thèse est construite en trois parties. La première est tout d’abord consacrée à une analyse réflexive de l’engagement ethnographique qui prend la rue comme terrain, et aux diverses formes de relation et de visibilité auquel conduit ce choix. Le cadre théorique et méthodologique affirme en particulier des positions méthodologiques et théoriques à l’égard de l’informalité. On y trouve également une acception élargie de la production, qui inclut les métiers urbains de service, ainsi que la nécessité d’étudier ensemble production et reproduction pour lire l’agencement des rapports sociaux. La seconde partie s’emploie à la reconstruction de la genèse de la division sociale du travail au Cameroun, dans un contexte colonial de « mise en valeur » et dans celui, postérieur à l’indépendance, des étapes de mutations économiques ayant affecté les logiques et formes de mise au travail des hommes et des femmes et produit une forme spécifique de séparation entre production et reproduction. En quatre périodes historiques, on y lit ainsi une généalogie des formes d’emplois urbains et des rapports sociaux qui les structurent, et tout particulièrement les rapports de sexe, de classe et de génération, inscrite dans le cadre du capitalisme global. Dans la troisième partie l’analyse du matériau empirique récolté pendant le travail de terrain et au-delà permet d’analyser les inégalités sociales à Yaoundé, de décrire des modes de vie et leurs difficultés matérielles et d’éclairer les stratégies pour faire face à la pauvreté. L’ethnographie révèle la division sociale du travail et des positions dans les métiers urbains, organisée autour de l’extorsion de surtravail sous forme de rente, sous diverses modalités, en une compétition forcenée, qui aboutit à reléguer les femmes et les enfants aux tâches de reproduction sociale, sans pour autant les écarter des tâches de production. Cette thèse de sociologie prend le parti d’inscrire l’analyse des métiers urbains dans une socio-histoire du capitalisme et de son implantation au Cameroun. Elle dépasse les catégories de travail formel / informel pour faire l’analyse matérialiste des formes de mise au travail articulée avec celle d’étudier ensemble, et non de façon dissociée, la production et la reproduction, à la lumière des rapports sociaux de sexe, de race, de classe et de génération. Cette thèse éclaire non seulement les rapports de domination et d’exploitation, mais aussi les formes de résistance et d’agencéité, au prisme de deux outils conceptuels qu’elle forge et enracine soigneusement : celui de régime libéral communautaire, et celui de rapport de rente d’exploitation. / The research relates to urban workers in Cameroon. As part of a theoretical inquiry, the manner in which we produce was given a fresh approach, in a new conception of work. To that end, the author has moved away from the tenets of the sociology of work to consider the city as a unit of production of useful services. That made it possible to widen the analysis in terms of work relations and grasp the dynamics of conflict, domination and exploitation, and also of change in the activities covered. The analysis is focussed on the forms employed in urban trades in Cameroon, by showing their characteristics. The decision to give that examination a historical perspective has made it possible to show that some trades have acquired a structuring role in the urban relations of production in Cameroon. That is true of the taxi services trade, which occupies a hegemonic place. Without being anachronistic or ethnocentric, it would appear that this area of work plays the part played by small artisans in English urban centres during the emergence of industrial capitalism in that country as described so well by E.P. Thompson. With their collective industry institutions, these workers have had a structuring role in the transformation of relations with work, and have provided leadership in social struggles. This ethnographic study in Yaoundé took place in a social atmosphere of apparent stability. Indeed, from the people’s protest movements of ‘dead cities’ in the early 1990s to the ‘hunger riots’ in 2008, Cameroon was experiencing a situation of permanent insurrection. When the author toured the country in 2010, the protests seem to have died down. That was certainly a forced break, in the face of violent repression by the government. The field work was therefore carried out during that apparent lull in 2010-2011, 2012 and 2015.The aim was to study the issue of the work and social reproduction of urban workers in Cameroon. What are its forms and determinants ? How has it changed in the course of the years since the start of development under colonial rule up to the contemporary period of structural adjustment ? How do the people get organised when they are excluded from the system of ordinary law ? The author believes that to address those questions, it is of relevance to use a sociohistorical approach that articulates work relations of class, race, gender and also generation.