Which farmers benefit the most from Bt corn adoption? Estimating heterogeneity effects in the Philippines

The potential contributions of new biotechnologies to sustainable food and income security have been the subject of widespread discussions around the turn of the 21st century. But distributional issues of which segments of adopters of genetically modified (GM) crops benefit the most have not been given ample attention). Using propensity scores, we apply the (a) stratification‐multilevel method of estimating heterogeneous treatment effects; and the (b) matching‐smoothing method of estimating heterogeneous treatment effects proposed by Xie et al. We find that the incidence of higher yields, lower insecticide use, and reduced seed utilization in the Philippines diminishes progressively as a farmer's propensity to adopt Bt corn increases. Farmers with a low propensity to adopt Bt are those who farm smaller, nonirrigated farms located farther from seed suppliers and farmers without previous training on pest identification. In most cases, while these farmers are typically poorer farmers in smaller parcels, cannot afford irrigation and are situated in remote areas away from easily accessible seed suppliers, there is no evidence, however, that profits differ across farmers with varying propensities to adopt the Bt variety.     

Cropland use,yields, and droughts: spatial data modeling for Burkina Faso and Niger

For countries with recurrent droughts, the design of drought impact mitigation measures could benefit from analyses of determinants of yields and prices of local crops at regional and district level. This study applies dynamic spatial panel data regression models to yields and prices of four major food crops across regions of Burkina Faso and Niger, over sample periods between 1984 and 2006. Results lend support to mainly simultaneous spatial spillovers, particularly for millet and cowpea prices and sorghum yields in Niger, and maize yields in Burkina Faso. After accounting for these effects, most crop yields are found to be weakly price‐responsive, as envisaged by a supply‐side geographical diffusion hypothesis. Seasonal rainfall elasticity estimates suggest that dominant food crops have slight advantage margins in terms of relative resilience to rainfall shortages. However, this result is to be weighed against low millet yields in Niger, and marked drops in sorghum yields during officially declared droughts in Burkina Faso.     

Food insecurity,income inequality,and the changing comparative advantage in world agriculture

I would like to argue in this article that in the process of economic development in land‐poor countries in Asia, agriculture faces three distinctly different problems: food insecurity, sectoral income inequality, and the declining food self‐sufficiency associated with the declining comparative advantage in agriculture at the high‐income stage. Massive imports of food grains to Asia, if they occur, will aggravate the world food shortage, which will have significant implications for the poverty incidence in the world. I argue that in order to avoid such a tragedy, Asia should expand farm size to reduce labor cost by adopting large‐scale mechanization, sub‐Saharan Africa should realize a green revolution in grain production, and Latin America should further expand its grain production capacity.     

Valuation of ecosystem services provided by irrigated rice agriculture in Thailand: a choice experiment considering attribute nonattendance

This research investigates how the public of a middle‐income country, Thailand, values ecosystem services associated with irrigated rice agriculture using a choice experiment. The results show a significant willingness to pay for services such as drought mitigation, water quality and the environment and maintenance of rural lifestyles and rice landscapes. The iterative procedure developed to fully analyze the incidence of attribute nonattendance (ANA) improved the model fit when compared with a multinomial logit model or an ANA model with potentially only one attribute ignored at a time (ANA‐1). Moreover, the inferred probability of the class of respondents having attended all attributes was 45%, compared to 9% with ANA‐1 model. However, it also suggests that 55% of the respondents made their choices by considering only two of the five attributes. Finally, this research also suggests that failing to consider ANA does not change the public ranking of scenarios contrasted by the services they would provide but would overestimate the WTP for these scenarios.     

Demand for meat and dairy products by Turkish households: a Bayesian censored system approach

We extend the Tobit (censored) linear equation system procedure to utility‐theoretic demand functions, along with a mapping mechanism to impose the adding‐up restriction implied by consumer utility maximization theory—a theoretical restriction very often ignored in previous empirical studies with censored demand systems. In this context, the Bayesian Markov Chain Monte Carlo (MCMC) procedure is applied to the censored linear approximate almost ideal demand system (LAIDS) for 12 food products, using data from the Turkish Household Expenditure Survey. All own‐price elasticities are negative and expenditure elasticities positive. Uncompensated own‐price elasticities for rural households are generally much higher than those for their urban peers, though demand for most food products are own‐price elastic for both types of households. The differential patterns in demand elasticities between urban and rural households become even more evident (almost twice) as relatively more expensive foodstuffs are consumed, showing that accessibilities to alternative products have made rural Turkish households more cognizant toward price changes in foods. Household characteristics play a key role in food expenditures, notably so in urban areas, and regional and seasonal differences are also present.     

The predictive accuracy of credit ratings: Measurement and statistical inference

Credit ratings are ordinal predictions of the default risk of an obligor. The most commonly used measure for evaluating their predictive accuracy is the Accuracy Ratio, or equivalently, the area under the ROC curve. The disadvantages of these measures are that they treat default as a binary variable, thus neglecting the timing of default events, and they fail to use all of the information available from censored observations. We present an alternative measure which is related to the Accuracy Ratio but does not suffer from these drawbacks. As a second contribution, we study statistical inference for the Accuracy Ratio and the proposed measure in the case of multiple cohorts of obligors with overlapping lifetimes. We derive methods which use more sample information and lead to tests which are more powerful than alternatives which filter just the independent part of the dataset. All procedures are illustrated in the empirical section using a dataset of S&P Credit Ratings.     

Impacts of Market Reform on Spatial Volatility of Maize Prices in Tanzania

Maize is one of the major staples and cash crops for many Tanzanians. Excessive volatility of maize prices destabilises farm income in maize‐growing regions and is likely to jeopardise nutrition and investment in many poor rural communities. This study investigates whether market reform policies in Tanzania have increased the volatility of maize prices, and identifies regional characteristics that can be attributed to the spatial price volatility. To achieve the objectives, an autoregressive conditional heteroskedasticity in mean (ARCH‐M) model is developed and estimated in this study. Results show that the reforms have increased farm‐gate prices and overall price volatility. Maize prices are lower in surplus and less developed regions than those in deficit and developed regions. Results also show that the developed and maize‐deficit regions, and regions bordering other countries have experienced less volatile prices than less developed, maize‐surplus and non‐bordering regions. Our findings indicate that investments in communication and transportation infrastructures from government and donor countries are likely to increase inter‐regional and international trade, thereby reducing the spatial price volatility in Tanzanian maize prices in the long run.     

Performance rating and yardstick competition in social service provision

This paper investigates whether national evaluation of decentralised government performance tends, by lessening local information spill-overs, to reduce the scope for local performance comparisons and consequently to lower the extent of spatial auto-correlation among local government expenditures. It analyses local government expenditures on personal social services in the UK before and after the introduction of a national performance assessment system (SSPR, Social Services Performance Rating) that would attribute a rating to each local authority. The empirical evidence is consistent with the hypothesis that the SSPR has reduced local yardstick competition.     

Effects of employees’ opportunities to influence in-store music on sales: Evidence from a field experiment

The effects of in-store music on consumer behavior have attracted much attention in the marketing literature, but surprisingly few studies have investigated in-store music in relation to employees. By conducting a field experiment in eight Filippa K fashion stores in Stockholm, Sweden, we investigate whether it is beneficial for store owners to give employees more opportunities to influence the in-store music. We randomly assigned the stores into a treatment group and a control group, with the employees in the treatment stores having the opportunity to influence the in-store music through an app developed by Soundtrack Your Brand (SYB). The experiment lasted 56 weeks and sales data were also gathered 22 weeks before the experiment, resulting in a total of 4626 observations. Our results show that sales decreased by 6% when the employees had the opportunity to influence the music played in the store, and the effect is driven by a reduction in sales of women's clothing. Interviews with the employees revealed that they had diverse music preferences, frequently changed songs, and preferred to play high-intensity songs. Employees thus seem to make choices regarding the in-store music that reduce sales, implying that store owners might want to limit their opportunities to influence the background music.     

Bivariate income distributions for assessing inequality and poverty under dependent samples

As indicators of social welfare, the incidence of inequality and poverty is of ongoing concern to policy makers and researchers alike. Of particular interest are the changes in inequality and poverty over time, which are typically assessed through the estimation of income distributions. From this, income inequality and poverty measures, along with their differences and standard errors, can be derived and compared. With panel data becoming more frequently used to make such comparisons, traditional methods which treat income distributions from different years independently and estimate them on a univariate basis, fail to capture the dependence inherent in a sample taken from a panel study. Consequently, parameter estimates are likely to be less efficient, and the standard errors for between-year differences in various inequality and poverty measures will be incorrect. This paper addresses the issue of sample dependence by suggesting a number of bivariate distributions, with Singh–Maddala or Dagum marginals, for a partially dependent sample of household income for two years. Specifically, the distributions considered are the bivariate Singh–Maddala distribution, proposed by Takahasi (1965), and bivariate distributions belonging to the copula class of multivariate distributions, which are an increasingly popular approach to modelling joint distributions. Each bivariate income distribution is estimated via full information maximum likelihood using data from the Household, Income and Labour Dynamics in Australia (HILDA) Survey for 2001 and 2005. Parameter estimates for each bivariate income distribution are used to obtain values for mean income and modal income, the Gini inequality coefficient and the headcount ratio poverty measure, along with their differences, enabling the assessment of changes in such measures over time. In addition, the standard errors of each summary measure and their differences, which are of particular interest in this analysis, are calculated using the delta method.