Do returns to education depend on how and whom you ask?

Returns to education remain an important parameter of interest in economic analysis. A large literature estimates these returns, often carefully addressing issues such as selection into wage employment and endogeneity in terms of completed schooling. There has been much less exploration of whether the estimates of Mincerian returns depend on how information about wage work is collected. Relying on a survey experiment in Tanzania, this paper finds that estimates of the returns to education vary by questionnaire design, but not by whether the information on employment and wages is self-reported or collected by a proxy respondent. The differences derived from questionnaire type are substantial, varying from higher returns of 5 percentage points among the most well educated men to 16 percentage points among the least well educated women. These differences are at magnitudes similar to the bias in ordinary least squares estimation, which receives considerable attention in the literature. The findings demonstrate that survey design matters in the estimation of returns to schooling and that care is needed in comparing across contexts and over time, particularly if the data are generated through different surveys

Out of the shadows: Classifying economies by the extent and nature of employment in the informal economy

Given the prevalence of informality, this article proposes a typology for classifying countries by the extent and nature of employment in the informal economy, rather than by the composition of their formal economies. The author analyses ILO data on employment in the informal economy in 36 developing countries, and shows that there is a significant correlation between cross-national variations in the degree and intensity of informalization and cross-national variations in social and economic indicators such as levels of GNP per capita, corruption, poverty, taxation and social contributions. The article concludes by discussing implications for theory and policy

Determinants of the level of informality of informal micro-enterprises: some evidence from the city of Lahore, Pakistan

Recognizing that enterprises operate at varying levels of informality, this paper evaluates the determinants of their degree of informality. Reporting a 2012 survey of 300 informal micro-enterprises in the city of Lahore in Pakistan, the finding is that the key predictors of their level of informality are the characteristics of the entrepreneur and enterprise, rather than their motives or the wider formal and informal institutional compliance environment. Lower degrees of informality are associated with women, older, educated and higher income entrepreneurs and older enterprises with employees in the manufacturing sector. The paper concludes by discussing the theoretical and policy implications

The Role of Mobile Phones in Tanzania’s Informal Construction Sector:The Case of Dar es Salaam

The Pierre Auger Observatory is currently the largest detector for measurements of cosmic rays with energies beyond 10^18 eV. It uses a hybrid detection method with fluorescence telescopes and surface detector stations. Cosmic rays with energies above 10^15 eV cannot be studied directly but they interact with the atmosphere and produce secondary particle cascades, called extensive air shower. These air showers carry information about the energy, the arrival direction and the chemical composition of the primary cosmic ray particle. The fluorescence telescopes measure the longitudinal air shower profile, whereas the surface detector stations study the lateral profile on the ground. The combination of both detectors provides measurements of cosmic rays with high accuracy.This thesis is focused on the study of the chemical composition of cosmic rays with the virtual fluorescence telescope HECO, which is the combination of the low energy enhancement HEAT (High Elevation Auger Telescopes) and the Coihueco telescope station. HEAT consists of 3 additional fluorescence telescopes, extending the energy range down to below 10^17.0 eV. The cosmic rays with energies between 10^17 eV to 10^18.4 eV are studied, which is the expected transition region from galactic to extra galactic cosmic rays.For the analysis of the chemical composition the atmospheric depth of the air shower maximum Xmax is used. The distribution of Xmax is depending on the atomic mass of the primary cosmic ray particle.An improved profile reconstruction using air shower universality is introduced in the reconstruction and several cross checks on the acquired data and simulations are performed. A complete Monte Carlo based composition analysis is performed to validate the analysis method. The systematic uncertainties of the analysis are studied in detail. The resulting first moments, the mean and the variance of the measured Xmax-distribution per energy bin are compared to theoretical predictions from current cosmic ray interaction models. Additionally, a new fit method is introduced to fit chemical composition fractions based on prediction from interaction models. A parametrization based on Gumbel statistics and air shower simulation is used to describe the Xmax-distribution as a function of energy and primary atomic mass. A superposition model of these parametrization is fitted on a simulated scenario to find the optimal fit routine. The method is applied on the measured Xmax data including all know systematic uncertainties. The findings of this thesis are compared to published results of other experiments. The results of all interaction models suggest a heavy composition at 10^17.0 eV that becomes lighter up to 10^18.4 eV, where it is composed of a mixture of nuclei with light atomic masses