analysts incentives and street earnings we examine whether analysts incentives are associated with street earnings because prior research argues that analysts incentives to promote stocks increase in the extent to which the stock exhibits glamour characteristics we predict that analysts are more likely to make income increasing adjustments in determining street earnings for glamour stocks than for value stocks we find that analysts are more likely to exclude expense items from street earnings for glamour stocks than for value stocks and that excluded expense items help predict future earnings for glamour stocks but not for value stocks overall our results suggest that analysts self interest influences street earnings and this self interest leads to street earnings that are less useful in predicting future earnings for glamour stocks

analysts gaap earnings forecasts and their implications for accounting research abstract we use newly available gaap forecasts to document that traditionally identified gaap forecast errors contain 37 measurement error correcting for this measurement error we settle a long standing debate regarding investor preference for gaap versus non gaap earnings and provide strong evidence of a preference for non gaap earnings we also revisit the use of non gaap exclusions to meet analysts forecasts when gaap earnings fall short results indicate that 34 of these traditionally identified meet or beat firms are misidentified due to measurement error and this error masks evidence that firms more frequently exclude transitory rather than recurring expenses for meet or beat purposes

a discussion of assessing the relative informativeness and permanence of pro forma earnings and gaap operating earnings abstract by analyzing a carefully constructed earnings announcements sample that discloses a pro forma earnings number bhattacharya et al j account econom 36 1 3 2003 contribute to recent research documenting increasing differences between earnings as defined by generally accepted accounting principles gaap and alternative earnings definitions followed by capital markets the paper provides interesting descriptive data on pro forma earnings per share relative to both gaap earnings per share and actual earnings per share as tracked by i b e s also the authors conduct tests of the relative informativeness and persistence of these three earnings measures econometric and data limitations inhibit the inferences that can be drawn from some of these tests

changes in the value relevance of earnings and book values over the past forty years this paper investigates systematic changes in the value relevance of earnings and book values over time we report three primary findings first contrary to claims in the professional literature the combined value relevance of earnings and book values has not declined over the past forty years and in fact appears to have increased slightly second while the incremental value relevance of bottom line earnings has declined it has been replaced by increasing value relevance of book values finally much of the shift in value relevance fiom earnings to book values can be explained by the increasing frequency and magnitude of one time items the increasing frequency of negative earnings and changes in average firm size and intangible intensity across time

comparing the post earnings announcement drift for surprises calculated from analyst and time series forecasts post earnings announcement drift is the tendency for a stock s cumulative abnormal returns to drift in the direction of an earnings surprise for several weeks following an earnings announcement we show that the drift is significantly larger when defining the earnings surprise using analysts forecasts and actual earnings from i b e s than when using a time series model based on compustat earnings data neither compustat s policy of restating earnings nor the inclusion of special items in reported earnings contribute significantly to the disparity in drift magnitudes rather our results suggest that this disparity is attributable to differences between analyst forecasts and those of time series models or at least to factors correlated with these differences further we document that analyst forecasts lead to return patterns around future earnings announcements that differ from those observed when using time series models suggesting that the two types of surprises may capture somewhat different forms of mispricing

the changing landscape of accrual accounting a fundamental property of accrual accounting is to smooth temporary timing fluctuations in operating cash flows indicating an inherent negative correlation between accruals and cash flows we show that the overall correlation between accruals and cash flows has dramatically declined in magnitude over the past half century and has largely disappeared in more recent years the adjusted r 2 from regressing changes in accruals on changes in cash flows drops from about 70 90 in the 1960s to near zero under 20 in more recent years in exploring potential reasons for the observed attenuation we find that increases in non timing related accrual recognition as proxied by one time and nonoperating items and the frequency of loss firm years explain the majority of the overall decline on the other hand temporal changes in the matching between revenues and expenses and the growth of intangible intensive industries play only a limited role in explaining the observed attenuation finally the relative decline of the timing role of accruals does not appear to be associated with an increase in the asymmetrically timely loss recognition role

truthfulness in accounting how to discriminate accounting manipulators from non manipulators accountants preparing information are in a position to manipulate the view of economic reality presented in such information to interested parties these manipulations can be regarded as morally reprehensible because they are not fair to users they involve in an unjust exercise of power and they tend to weaken the authority of accounting regulators this paper develops a model for detecting earnings manipulators using financial statements ratios in a sample of spanish listed companies our results provide evidence that accounting data can be extremely useful in detecting manipulators this approach can be used by a large category of users of accounting information among which we can cite stock exchange supervisors or investing professionals

management earnings forecasts and value of analyst forecast revisions this study examines the stock price reactions to analyst forecast revisions around earnings announcements to test whether preannouncement forecasts reflect analysts private information or piggybacking on confounding events and news we find that management earnings forecasts influence the timing and precision of analyst forecasts more importantly evidence suggests that prior studies finding of weaker stronger stock price responses to forecast revisions in the period immediately after before the prior quarter earnings announcement disappears once management earnings forecasts are controlled for to the extent that management earnings forecasts are public disclosures our results suggest that the importance of analysts information discovery role documented in prior studies is likely to be overstated this paper was accepted by wei jiang finance

agricultural household models extensions applications and policy this book presents the basic model of an agricultural household that underlies most of the case studies undertaken so far the model assumes that households are price takers and is therefore recursive the decisions modeled include those affecting production and the demand for inputs and those affecting consumption and the supply of labor comparative results on selected elasticities are presented for a number of economies the empirical significance of the approach is demonstrated in a comparison of models that treat production and consumption decisions separately and those in which the decisionmaking process is recursive the book summarizes the implications of agricultural pricing policy for the welfare of farm households marketed surplus the demand for nonagricultural goods and services the rural labor market budget revenues and foreign exchange earnings in addition it is shown that the basic model can be extended in order to explore the effects of government policy on crop composition nutritional status health saving and investment and to provide a more comprehensive analysis of the effects on budget revenues and foreign exchange earnings methodological topics primarily the data requirements of the basic model and its extensions along with aggregation market interaction uncertainty and market imperfections are discussed the most important methodological issues the question of the recursive property of these models is also discussed

physical and human capital and brazilian regional growth a spatial econometric approach for the period 1970 2010 carvalho r and silveira neto r physical and human capital and brazilian regional growth a spatial econometric approach for the period 1970 2010 regional studies this paper identifies the determinants of economic growth and analyses the dynamics of income using a panel of 522 brazilian micro regions for period 1970 2010 based on the spatial extension of the mankiw romer weil mrw model and explicitly considering both physical and human capital the parameters of a spatial durbin model sdm with fixed effects are estimated the direct and indirect impacts of the determinants of regional growth are then calculated the results indicate strong spatial dependence among brazilian micro regions and that investments in both physical and human capital are important for the growth of the brazilian regional economies

child labor and agricultural shocks this paper examines the relationship between household income shocks and child labor in particular we investigate the extent to which transitory income shocks lead to increases in child labor and whether household asset holdings mitigate the effects of these shocks using data from a household panel survey in tanzania we find that both relationships are significant we investigate mechanisms that could account for these results including buffer stocks and borrowing

reducing child malnutrition how far does income growth take us how rapidly will child malnutrition respond to income growth this article explores that question using household survey data from 12 countries as well as data on malnutrition rates in a cross section of countries since the 1970s both forms of analysis yield similar results increases in income at the household and national levels imply similar rates of reduction in malnutrition using these estimates and better than historical income growth rates the article finds that the millennium development goal of halving the prevalence of underweight children by 2015 is unlikely to be met through income growth alone what is needed to accelerate reductions in malnutrition is a balanced strategy of income growth and investment in more direct interventions

ex ante and ex post labor supply response to risk in a low income area abstract this paper tests for ex ante and ex post labor supply responses to weather risk for rural indian farm households the analysis uses panel data on 2115 households spanning 13 states in rural india merged with a 22 year series of district level rainfall data ex ante households facing riskier distributions of rainfall are more likely to participate in the labor market ex post unexpectedly bad weather and low rainfall increase labor force participation

discussion of analysts treatment of non recurring items in street earnings and loss function assumptions in rational expectations tests on financial analysts earnings forecasts abstract this article discusses papers by gu and chen analysts treatment of non recurring items in street earnings and by basu and markov loss function assumptions in rational expectations tests on financial analysts earnings forecasts these two papers address issues associated with the rationality or expertise of analysts and both papers interpret their evidence as supporting the hypothesis that analysts do a good job of processing information and forecasting earnings results that contrast with a growing literature that is critical of the incentives and abilities of analysts my article critiques their methods and conclusions and suggests areas for future research

are estimates of calorie income fxelasticities too high a recalibration of the plausible range abstract the wide range of calorie income elasticities in the literature results in large part from the particular calorie and income variables used for estimation elasticities across four estimation techniques and four calorie income variable pairs for a sample of philippine farm households ranged from 0 03 to 0 59 estimates associated with calorie availability are biased upwards first because random errors in measuring food purchases are transmitted by construction both to calorie availability and total expenditures and second because the residual difference between family calorie intake and household calorie availability will often increase with income the calorie intake total expenditure variable pair gives the preferred elasticity estimate in the 0 08 0 14 range

prices credit markets and child growth in low income rural areas in this paper it is argued that fluctuations in child growth in rural areas of bangladesh during and after severe floods in i988 can provide insight into the structure of credit markets a model of intertemporal resource allocation is developed and euler equations relating growth patterns of children to the cost of borrowing by household are then derived from the model the evidence indicates that although some of the variation in growth patterns over the relevant period may be attributed to variation in illness and the price of rice growth patterns for children in landless households were influenced by credit market imperfections this paper links two prominent strands of research in economic development the first strand examines the extent to which households in poor rural economies are able to protect themselves from the adverse weather and other shocks that importantly influence earnings in underdeveloped areas while it has long been thought that credit market imperfections and other forms of market failure make it difficult for poor individuals in these economies to smooth consumption both within and across years there remains some question about the magnitude and pervasiveness of these imperfections while there is evidence that fluctuations in economic conditions result in inefficient allocation of resources e g morduch 1990 rosenzweig and wolpin i993 some recent papers have emphasised the fact that consumption patterns of households in the same village comove in a manner consistent with the idea that a substantial fraction of idiosyncratic variation in income is effectively

conservatism and cross sectional variation in the post earnings announcement drift accounting conservatism allows me to identify a previously undocumented source of predictable cross sectional variation in standardized unexpected earnings autocorrelations viz the sign of the most recent earnings realization and present evidence that the market ignores this variation loss effect it is possible to earn returns higher than from the bernard and thomas 1990 strategy by incorporating this feature additionally the paper shows that the loss effect is different from the cross quarter effect shown by rangan and sloan 1998 and it is possible to combine the two effects to earn returns higher than either strategy alone thus the paper corroborates the bernard and thomas finding that stock prices fail to reflect the extent to which quarterly earnings series differ from a seasonal random walk and extends it by showing that the market systematically underestimates time series properties resulting from accounting conservatism

the distributional effects of emissions taxation in brazil and their implications for climate policy abstract the emission of greenhouse gases ghg generated by human activity is a major cause of global warming and climate change there is considerable debate about the choice of the best mechanism to reduce emissions under a climate policy the aim of this paper is to measure the impact of a policy of taxing ghg emissions on the brazilian economy as a whole and on different household groups based on income levels in 2009 the following databases were used supply and use tables household budget survey national household sample survey and emissions data from the brazilian ministry of science and technology and innovation a price system from a national input output model that incorporates the intensity of ghg emissions is used as well as a consumption vector broken down into ten representative households with different income levels the main results indicate that this taxation system was slightly regressive and had a small negative impact on output there were however significant emissions reductions

accounting for inequality trends decomposition analyses for the uk 1971 86 eight explanations for uk income inequality trends between 1971 and 1986 are assessed by pooling evidence from inequality index decompositions by population sub group and by income source the principal causes of the aggregate trends were a mixture of changes in earnings inequality employment structure and unemployment but this mixture changed over time the impact of wage inequality changes on income inequality changes fell during the 1970s and 1980s reflecting the secular decline in the importance of employment earnings for household income packages unemployment changes had their largest impact at the start of the 1980s between 1981 and 1986 self employment income changes appear to have had the largest influence

do investors see through mistakes in reported earnings this study investigates whether investors see through materially misstated earnings and whether they anticipate earnings restatements for firms that restate at least one annual report we find that investors are misled by mistakes in reported earnings at the time of initial earnings announcements investors react positively to the component of the favorable earnings surprise that will subsequently be restated and they attach the same valuation to it as to the true earnings surprise we also find that investors anticipate the subsequent downward restatements and start marking stock prices down several months before a restatement announcement so that the full impact of a restatement is about three times as large as the restatement announcement effect indeed we show that investors punish restating firms because the stock price gains that shareholders enjoy when firms initially announce overstated earnings are more than reversed by the time of the restatement announcement

the impact of income and non income shocks on child labor evidence from a panel survey of tanzania summary this paper investigates the impact of income and non income shocks on child labor using a model in which the household maximizes utility from consumption as well as human capital development of the child we also investigate if access to credit and household assets act as buffers against transitory shocks our results indicate significant effects of agricultural shocks on the child s overall work hours and agricultural work hours with higher effects for boys crop shocks also have significant adverse effects on school attendance with girls experiencing a more than 70 increase in the probability of quitting schooling the results also indicate that access to a bank account has a buffering effect on the impact of shocks on child hunger having a bank account reduces both male child labor and household work hours of a girl child while assets reduce working hours of girls we do not find it having a significant effect on boys we also do not see assets to act as a buffer against shocks

income smoothing and consumption smoothing one way that risk averse households protect consumption levels is to borrow and use insurance mechanisms another way common in low income economies is to diversify economic activities and make conservative production and employment choices households thus tend toward limiting exposure only to shocks that can be handled with available credit and insurance typically both types of mechanisms are studied independently but much more can be learned by studying them together first we obtain a more complete picture of risks costs and insurance possibilities second it opens the way to considering biases in standard tests of credit and insurance

gaap versus the street an empirical assessment of two alternative definitions of earnings managers security analysts investors and the press rely increasingly on modified definitions of gaap net income known by such names as operating and pro forma earnings we document this phenomenon and discuss competing explanations for the recent rise in the use of such modified earnings numbers and implications for the interpretation of related accounting research our results show that over the past 20 years there has been a dramatic increase in the frequency and magnitude of cases where gaap and street earnings differ further there is a very strong bias toward the reporting of a street earnings number that exceeds the gaap earnings number we also show that the market response to the street earnings number has displaced gaap earnings as a primary determinant of stock prices finally through an analysis of earnings releases we show that management has taken a proactive role in defining and emphasizing the street number when communicating to analysts and investors

do analysts understand the economic and reporting complexities of derivatives we investigate whether and how the complexity of derivatives influences analysts earnings forecast properties using a difference in differences design we find that relative to a matched control sample of non users analysts earnings forecasts for new derivatives users are less accurate and more dispersed after derivatives initiation these results do not appear to be driven by the economic complexity of derivatives but rather the financial reporting of such economic complexity overall despite their financial expertise analysts routinely misjudge the earnings implications of firms derivatives activity however we find evidence that a series of derivatives accounting standards has helped analysts improve their forecasts over time

temperature changes household consumption and internal migration evidence from tanzania large rural urban wage gaps observed in many developing countries are suggestive of barriers to migration that keep potential migrants in rural areas using long panel data spanning nearly two decades i study the extent to which migration rates are constrained by liquidity constraints in rural tanzania the analysis begins by quantifying the impact of weather variation on household welfare the results show how household consumption co moves with temperature rendering households vulnerable to local weather events these temperature induced income shocks are then found to inhibit long term migration among men thus preventing them from tapping into the opportunities brought about by geographical mobility

is variety the spice of life implications for calorie intake the income elasticity of calories generally is substantially smaller than the income elasticity of food expenditure one reason may be an increasing concern for food variety as incomes increase food variety can be linked with two characteristics of food indifference curves 1 curvature and 2 location of the curves relative to the axes estimates suggest increasing taste for variety as food budgets increase therefore such taste for variety apparently underlies in part the low income elasticities for calorie demand which in turn cast doubt on the world bank assertion that the nutrient intakes of poor populations will improve rapidly with income copyright 1989 by mit press

will developing country nutrition improve with income a case study for rural south india aggregate estimates of food expenditure are consistent with such a possibility implying income expenditure elasticities close to one however the high degree of aggregation at which such estimates are made means that the considerable increase in price per nutrient as income increases is ignored and the nutrient elasticities are therefore overstated estimates for a rural south indian sample indicate that this bias is considerable and that the true nutrient elasticities with respect to income may be close to zero

non spatial government policies and regional income inequality in brazil silveira neto r da m and azzoni c r non spatial government policies and regional income inequality in brazil regional studies this paper uses both macro and micro data to analyse the role of social programmes in the recent reduction in brazilian regional income inequality convergence indicators are presented for different sources of regional income in the period 1995 2006 a decomposition of the gini indicator allows the identification of the role of each of these income sources with respect to the reduction of regional inequality during the period the results point out that both labour productivity and government non spatial policies mainly minimum wage changes and income transference programmes do have a role in explaining regional inequality reduction during the period silveira neto r da m et azzoni c r les politiques gouvernementales non spatiales et l ecart des revenus regionaux au bresil regional studies cet article emploie des donnees a la fois macroeconomiques et microeconomiqu

resilience thresholds to temperature anomalies a long run test for rural tanzania abstract the existence of thresholds constitutes an important frontier topic for resilience analysis and measurement this paper contributes to the literature by identifying critical resilience thresholds below which rural tanzanian households are unable to absorb the negative effects of temperature anomalies on long run growth to make up for the lack of long micro panels we generate a synthetic panel covering the time span 2000 2013 we show that 25 47 of households in our sample lie below the estimated thresholds the evidence of resilience driven regime shifts and non linear dynamics has important implications for adaptation to climate change in developing countries and is of significant interest for policy interventions

health nutrition and economic development the relationship between health and economic development is explored focusing on nutrition based health indicators the spotlight is placed on the inter related feedbacks between the influence of health on productivity on one hand and the influence of income on health status on the other disentangling causality in these relationships has preoccupied much of the literature we evaluate different empirical strategies that have been adopted and assess the results there is now a body of evidence based on careful empirical studies that demonstrates a causal relationship between health and labor productivity there is also evidence that at least among the very poor additional income is spent on improved nutrition there are two issues that have received little attention although we argue they are likely to be very important first measurement of health is discussed in detail evidence is presented on how taking into account differences in the extent of measurement error is critical for interpreting the impact of health on wages the same theme emerges in studies of the effect of income on health specifically calorie intake the key role of non linearities in these relationships is highlighted and we demonstrate that a good deal of the variation in estimates of income elasticities of demand for calories can be ascribed to the role of measurement and functional form authors

smoothing consumption by smoothing income hours of work responses to idiosyncratic agricultural shocks in rural india while research has demonstrated that farm households in developing economies are able to protect consumption from idiosyncratic crop shocks little evidence shows how this is achieved this paper examines the extent to which labor markets allow households to shift labor from farm to off farm employment and the extent to which such a shift explains the observed lack of correlation between consumption and idiosyncratic crop shocks the empirical analysis uses a novel measure of the idiosyncratic crop income shock which utilizes information on start of season cropping choices to more accurately estimate household expectations of weather

do bright line earnings surprises really affect stock price reactions several influential studies have concluded that earnings surprises just to the right or to the left of a hypothesized bright line produce distinct price reactions compared with surrounding earnings surprises because they convey special meaning in this study we examine whether previous inferences of asymmetric stock price reactions to bright line surprises are observed when empirical tests are designed to be consistent with a rational expectations equilibrium focusing on a small range of earnings surprises around hypothesized bright lines we find no evidence of asymmetric price reactions once investors ex ante expectation of bias in earnings surprises is controlled results from additional tests yield support for the external validity of the theoretical framework underlying our bright line pricing tests our findings suggest simple refinements to traditional bins comparison and regression tests for asymmetric price reactions to bright line earnings surprises which account for necessary conditions imp

how responsive is body weight to transitory income changes evidence from rural tanzania we use time series of rainfall to estimate the response of body weight to transitory changes in household income in rural tanzania we find that the response of body weight to income changes is positive on average but that the impact is highest for female children and lower for adults for female children a ten percent increase in household income implies an increase in body weight by about 0 4 kg in contrast the body weight of adolescents and young adults is virtually invariant to income changes

child growth shocks and food aid in rural ethiopia this brief summarizes the results of a gender impact evaluation study entitled child growth shocks and food aid in rural ethiopia conducted between 1995 and 1996 in ethiopia the study observed the impact of food aid on child growth and shocks in communities on the child level food aid has a positive significant impact on the growth in height of children the total amount of food aid appears on average to be sufficient to offset the negative effects of plot damage on child growth given the fact there remains a massive amount of child stunting there must be large amounts of mis targeting of aid girls seem to be more resilient to shocks than boys

the superiority and disciplining role of independent analysts abstract we show that although forecasts of independent analysts are less accurate ex post they yield forecast errors that are more strongly associated with abnormal stock returns this suggests that forecasts of independent analysts are superior to those of nonindependent analysts in representing ex ante market expectations we also show that forecasts of nonindependent analysts become more accurate and less biased and produce forecast errors more strongly associated with abnormal stock returns when independent analysts are following the same firms than when they are not this suggests that the presence of independent analysts disciplines the behavior of nonindependent analysts

the demand for food and calories we investigate nutrition and expenditure in rural maharashtra in india we estimate that the elasticity of calorie consumption with respect to total expenditure is 0 3 0 5 a range that is in accord with conventional wisdom the elasticity declines only slowly with levels of living and is far from the value of zero suggested by a recent revisionist literature in these indian data the calories necessary for a day s activity cost less than 5 percent of the daily wage which makes it implausible that income is constrained by nutrition rather than the other way around

why do eps forecast error and dispersion not vary with scale implications for analyst and managerial behavior we document a counter intuitive finding regarding analyst forecasts of quarterly earnings per share eps magnitudes of deviations from benchmarks individual forecasts versus consensus dispersion and consensus versus actual forecast error do not vary with scale seasonally differenced eps or time series forecast error also exhibits substantial lack of variation with scale but only for firms followed by analysts this lack of variation with scale is not observed for analyst and time series forecasts for a eps for some countries b sales and cash flows for all countries and c stock splits we propose and investigate different explanations for these puzzling regularities that have important implications for practice and research we believe the cause is managerial smoothing of eps designed to reduce across firm variation in eps volatility

temperature shocks short term growth and poverty thresholds evidence from rural tanzania using the lsms isa tanzania national panel survey by the world bank we study the relationship between rural household consumption growth and temperature shocks over the period 2008 2013 temperature shocks have a negative and significant impact on household growth only if their initial consumption lies below a critical threshold as such temperature shocks slow income convergence among households agricultural yields and labour productivity are the main transmission channels these findings support the schelling conjecture economic development would allow poor farming households to cope with climate change and closing the yield gap and modernizing agriculture is crucial for adaptation to the negative impacts of global warming

the intrahousehold demand for nutrients in rural south india individual estimates fixed effects and permanent income good estimates of nutrient intake responses to prices and income are very useful for the evaluation of the numerous efforts to improve nutrition in many developing countries through pricesubsidy and income generation policies we discuss three problems in standard estimates of these responses and then illustrate their implications for nutrient demand relations for a poor sample from rural south india 1 intra household nutrient allocations usually are ignored in this case nutrient intakes for females systematically have algebraically lower price elasticities than do those for males which may leave the females particularly vulnerable at times of food shortages 2 unobserved fixed effects may bias the estimates of responses to observed variables in this case not only the community fixed effects on which the previous literature has focused but also household and individual fixed effects are important failure to control for them results in substantial algebraically upward biases in many estimated price responses 3 most previous studies use current instead of permanent income which a priori may account for the low estimated income elasticities in this case however the use of permanent income does not change the conclusion that the nutrient intakes responses to income are quite small

have financial statements lost their relevance the authors explore the concern that financial statements no longer have the same relevance to investors that they had in the past they test for value relevance by measuring the total return that could have been earned from prior knowledge of financial statement information and by examining the explanatory power of accounting information on market values and annual market adjusted returns both analyses are applied to a broad sample of exchange listed and nasdaq firms for the 1952 94 period the authors find mixed evidence on value relevance of financial statement reporting during the test period

structuring investment and regional inequalities in the brazilian northeast abstractstructuring investment and regional inequalities in the brazilian northeast regional studies this paper evaluates the long run regional impacts of the construction of three oil refineries proposed for brazil s northeast ne region a dynamic interregional computable general equilibrium cge model was developed with 28 regions in the ne and the rest of brazil and 30 sectors the database construction methodology could be applied to any other country the main results of the refinery investment simulations in the ne indicate positive impacts in all regions however the construction and operation of these three refineries would generate an increase in intraregional inequalities on the other hand in the long run these investments could contribute to the ne gaining an increased relative share of brazilian gross domestic product gdp

the impact of positive and negative income changes on the height and weight of young children we estimate the impact of changes in unearned income on the height and weight of young children in a developing country as a source of income variation we use a change in the eligibility criteria

income and health in tanzania an instrumental variable approach there is a substantial debate over the direction of the causal relation between income and health this is important for our understanding of the health production process and for the policy debate over improving healthcare we instrument income with rainfall measurements by matching satellite information on timing and positioning of 21 rainfall stations to longitudinal data 1991 94 of over 4 000 individuals in 51 villages in tanzania a 10 increase in income reduces the number of illnesses by 0 02 we also find that a 10 increase in income implies an increase of about 0 1 vaccinations of children under six

natural natural experiments in economics the recent literature exploiting natural events as natural experiment instruments is reviewed to assess to what extent it has advanced empirical knowledge a weakness of the studies that adopt this approach is that the necessary set of behavioral market and technological assumptions made by the authors in justifying their interpretations of the estimates is often absent the methodology and findings from twenty studies are summarized and simple economic models are used to elucidate the implicit assumptions made by the authors and to demonstrate the sensitivity of the interpretations of the findings to the relaxation of some of these assumptions

crop diversification and child health empirical evidence from tanzania malnutrition is recognized as a major issue among low income households in developing countries with long term implications for economic development recently crop diversification has been considered as a strategy to improve nutrition and health however there is no systematic empirical evidence on the role played by crop diversification in improving human health we use three waves of the tanzania national panel survey to test the effect of crop diversification on child health we implement two instrumental variable approaches and perform several robustness checks to address potential endogeneity concerns we find a positive but small effect of an increase in crop diversification on child height for age z score through greater dietary diversity the effect is larger for subsistence households and children living in households with limited market access