No abstract

A large literature has used children’s birthdays to identify exposure to shocks and estimate their impacts on later outcomes. Using height-for-age z scores (HAZ) for more than 990,000 children in 62 countries from 163 Demographic and Health Surveys (DHS), we show how random errors in birth dates create artifacts in HAZ that can be used to diagnose the extent of age misreporting. The most important artifact is an upward gradient in HAZ by recorded month of birth (MOB) from start to end of calendar years, resulting in a large HAZ differential between December- and January-born children of –0.32 HAZ points. We observe a second artifact associated with round ages, with a downward gradient in HAZ by recorded age in months, and then an upward step after reaching ages 2, 3, and 4. These artifacts have previously been interpreted as actual health shocks. We show that they are not related to agroclimatic conditions but are instead linked to the type of calendar used and arise mainly when enumerators do not see the child’s birth registration cards. We explain the size of the December–January gap through simulation in which 11 % of children have their birth date replaced by a random month. We find a minor impact on the average stunting rate but a larger impact in specific error-prone surveys. We further show how misreporting MOB causes attenuation bias when MOB is used for identification of shock exposure as well as systematic bias in the impact on HAZ of events that occur early or late in each calendar year. Electronic supplementary material The online version of this article (10.1007/s13524-018-0753-9) contains supplementary material, which is available to authorized users.

This paper examines the extent to which recruitment ties affect individual wage outcomes in small and medium scale manufacturing firms. Based on a unique matched employer-employee dataset from Vietnam the authors find that there is a significant positive wage premium associated with obtaining a job through an informal contact, when controlling for standard determinants of wage compensation. Moreover, they show that the mechanism through which informal contacts affect wages depends on the type of recruitment tie used. The findings are robust across location, firm size categories, and different worker types.* Larsen and Torm (corresponding author):

Networks have been found to increase adoption of technology by providing information about the new technology (e.g., Conley and Udry, 2010). However, little is known about provision of necessary inputs for adoption through networks. Using data from an intervention in Tanzania, I discuss how a farmer's network can also affect the adoption of improved banana cultivation by providing seedlings. A solidarity chain principle obliged project farmers to pass on improved seedlings to other farmers free of charge. I provide a theoretical framework to guide intuition for the empirical results and suggest an empirical distinction between information and input provision through networks. Empirically, I find support for network effects through provision of both information and inputs, jointly boosting the network effect on adoption: a farmer is 39 percentage points more likely to adopt banana cultivation if there is at least one banana grower in the farmer's network compared to none. In this setting, it is not possible to fully disentangle the input and information channel. While the findings suggest that a solidarity chain principle could be an interesting avenue to boost local diffusion of new technologies, more research is needed to unpack the causal impact and the interplay with existing input markets.JEL classifications: D83, O13, O33, Q16

Severely reduced height-for-age due to undernutrition is widespread in young African children, with serious implications for their health and later economic productivity. It is primarily caused by growth faltering due to hunger spells in critical periods of early child development. We assess the impact on early childhood nutrition, measured as height-for-age, of an agricultural intervention that improved food security among smallholder farmers by providing them with a "basket" of new technology options. We find that height-for-age measures among children from participating households increased by about 0.9 standard deviations and the incidence of stunting among them decreased by about 18 percentage points. JEL classification: I15, O13, Q16Undernutrition is widespread and a key reason for poor child health in many developing countries. In Sub-Saharan Africa, around 40 percent of children under the age of five suffer from stunted growth, that is, severely reduced height-for-age relative to their growth potential (de Onis et al. 2011). Stunting is a result of periods of undernutrition in early childhood, and it has been found to have a series of adverse long-term effects in those who survive childhood. It is negatively associated with mental development