the demand for food products an analysis of interpurchase times and purchased quantities in this paper we study household purchase behaviour of storable food products an inventory model is developed in which the household chooses an optimal stock level of the product storage of the product is costly there is a fixed cost per purchase occasion and the market price is sometimes discounted because of price promotions we show that the optimal purchase policy is an s s policy the model is used to derive predictions on the correlations between interpurchase times and purchased quantities on the one hand and prices on the other these predictions are empirically verified using consumer panel data

privatisation in developing countries a review of the evidence and the policy lessons privatisation is widely promoted as a means of improving economic performance in developing countries however the policy remains controversial and the relative roles of ownership and other structural changes such as competition and regulation in promoting economic performance remain uncertain this article reviews the main empirical evidence on the impact of privatisation on economic performance in developing economies the evidence suggests that if privatisation is to improve performance over the longer term it needs to be complemented by policies that promote competition and effective state regulation and that privatisation works best in developing countries when it is integrated into a broader process of structural reform

competition and corporate performance are people right to think that competition improves corporate performance my investigations indicate first that there are some theoretical reasons for believing this hypothesis to be correct but they are not overwhelming furthermore the existing empirical evidence on this question is weak however the results reported here based on an analysis of around 670 u k companies do provide some support for this view most important i present evidence that competition as measured by increased numbers of competitors or by lower levels of rents is associated with a significantly higher rate of total factor productivity growth

how different is the efficiency of public and private water companies in asia several studies have compared the efficiency of publicly and privately owned water utilities and reached conflicting conclusions on the impact of ownership on efficiency this article provides further evidence by estimating a stochastic cost frontier for a sample of asian and pacific regional water companies the results show that efficiency is not significantly different in private companies than in public ones

a bootstrapped double hurdle analysis consumption of home produced food this article deals with home made food the consumption of such specific goods involves an important null consumption issue a two step procedure is used to estimate whether the decision to consume is distinct from the decision on the amount of consumption data from the 1991 french food consumption survey show the relevance of double hurdle models finally the estimation of cragg s model is improved with a new undersampling procedure numerous and sometimes opposite effects of household characteristics on the probability of consuming home produced food and on the amount consumed are obtained

firm size wage gaps job responsibility and hierarchical matching i present the fact that wage gaps due to firm size increase with job responsibility i use swedish data to determine whether wage gaps increase with a direct measure of job responsibility to compare the age patterns of the wage gaps for blue and white collar workers and to compare wages by job responsibility and spans of control with u s data i compare supervisory to nonsupervisory occupations and find that wage gaps increase with job responsibility for most occupational ladders this fact is consistent with hierarchical matching models in which the larger number of subordinates amplifies managerial talent

modeling food consumption decisions as a two step process this article evaluates the suitability of tobit analysis of food consumption patterns by comparing results generated by a tobit model and a modification with a two step decision process two samples of adult women were selected from the 1977 78 nationwide food consumption survey and the 1985 continuing survey of food intakes by individuals results show strong statistical evidence for questioning tobit analysis in examining food consumption decisions determinants of the decision to consume food within a particular food group often differ from the determinants of how much to consume particularly for more highly defined food groupings analysis of u s food consumption patterns and their dietary aspects with respect to consumer behavior has a long history traditionally ordinary least squares ols or some variant has been used in many studies where ols was not appropriate the tobit method was applied tobit allows for a discrete mass point for observations as well as a continuous range of values for the dependent variable this nonlinear method has yielded good results in a variety of studies e g mccracken and brandt lane and devaney and fraker this article examines the suitability of the tobit method for analysis of food consumption patterns the tobit method assumes that the decision to consume a given food item is the same as the decision about the amount of the food to consume ignoring the two step nature of the decision process may hamper understanding of true behavioral patterns lead to erroneous conclusions and generate incorrect policy recommendations this article compares results generated by a tobit model and a modification with a two step decision process in the next section the statistical methods used to test whether food consumption is a one or two step decision process are described the following sections discuss the variables and data present the results and consider the conclusions

from the fringe to the fore labor unions and employee compensation conventional wisdom suggests that labor unions raise worker wages while the newer empirical literature finds only negligible earnings effects i reconcile this apparent contradiction by arguing th

a double hurdle approach to modelling tobacco consumption in italy this article analyzes the determinants of tobacco expenditures for a sample of italian households a box cox double hurdle model adjusted for heteroscedasticity is estimated to account for separate individual decisions concerning smoking participation and tobacco consumption and to correct for nonnormality in the bivariate distribution of the error terms nested univariate and bivariate models are found to be excessively restrictive supporting the adequacy of a generalized specification estimation results show that consumption decisions are significantly affected by income and demographic characteristics in particular income positively impacts tobacco expenditure while participation probability substantially declines as age increases the existence of significant gender differences in both smoking participation and tobacco consumption patterns is found while high education and white collar occupation reduces the likelihood to smoke and tobacco expenditure levels single adult households have a lower

estimating consumption from expenditure data abstract most studies of distributional issues have focused on the distribution of income but the income information usually available suffers from well known deficiencies this paper explores an alternative approach to distributional analysis based instead on expenditure data in many countries including the united kingdom available household budget data provides information on expenditures only over a short period the problems that consequently arise in interpreting data of this sort are emphasised a general specification for the stochastic structure of expenditure data is presented and a procedure for estimating participant households underlying consumption from their observed expenditures developed and discussed

testing the infrequent purchases model using direct measurement of hidden consumption from food stocks survey reports of zero expenditure result from either genuine non consumption or purchases undertaken too infrequently to observe during a survey with hidden consumption from stocks infrequent purchase models rely on untested hypotheses to distinguish these types of zeros we test such models with data from an unusual survey where food stocks are measured at the start and end of the survey reference period parameter estimates using these direct measures of hidden consumption out of stocks are compared with estimates from infrequent purchase models that attempt to recover this hidden consumption the results suggest considerable bias when using the infrequent purchase models copyright 2012 oxford university press

carbon tax simulations using a household demand model abstract the main objective of this paper is to analyse consumer response and welfare effects due to changes in energy or environmental policy to achieve this objective we formulate and estimate an econometric model for non durable consumer demand in sweden that utilises micro and macro data in the simulations we consider two revenue neutral scenarios that both imply a doubling of the co2 tax one that returns the revenues in the form of a lower vat and one that subsidise public transport one conclusion from the simulations is that the co2 tax has regional distribution effects in the sense that household living in sparsely populated areas carry a larger share of the tax burden

privatization and employment a study of the jute industry in bangladesh this paper analyzes the effect of privatization upon employment in the bangladeshi jute textile industry privatization was partia and the selection of mills which were privatized was not based on current economic performance this provides us with a panel data set which permits reliable estimates of the effects of ownership on employment and output privatization has reduced employment of all categories of permanent workers significantly but the extent of employment reduction has been substantially greater among clerical workers and managers as compared to manual workers this implies that public sector excess employment benefited white collar workers who were both better off and better educated and suggests that public sector behaviour was clientelist rather than welfarist

estimating a demand system with nonnegativity constraints mexican meat demand a new information based approach for estimating systems of many equations with nonnegativity constraints is presented this approach called generalized maximum entropy gme is more practical and

the impact of tax reforms designed to encourage healthier grain consumption in this paper we simulate the effects of tax reforms aimed at encouraging healthier grain consumption we use a rich data set on household grain consumption in 2003 from the market research institute gfk sweden combined with information on the nutritional content of the consumption we estimate behavioral parameters which are used to simulate the impact on the average household of tax reforms entailing either a subsidy on commodities particularly rich in fiber or a subsidy of the fiber density in grain products our results suggest that to direct the fiber intake towards nutritional recommendations reforms with a substantial impact on consumer prices are required regardless of the type of subsidy implemented the increase in the intake of fiber is accompanied by unwanted increases in nutrients that are often overconsumed fat salt and sugar funding the subsidies by taxing these nutrients or less healthy commodities helps to counteract such developments

employer size and compensation the role of worker characteristics the substantial effect of employer size on wages health insurance and pension coverage is examined much of the size related variation in compensation is shown to result from the types of jobs and workers hired by large employers while firm and establishment size have similar effects on wages firm size effects clearly dominate in the provision of fringe benefits particularly for pensions worker and job types explain a larger share of the size related variation for wages than for health insurance or pension coverage possible explanations for these patterns are provided

calibrating benefit function transfer to assess the conservation reserve program benefit transfer offers an inexpensive alternative to conducting an original study to determine economic value unfortunately benefit transfers can also result in biased welfare estimates in this paper we suggest a method of calibrating the benefit transfer to reduce this bias an empirical example to determine the benefits of the conservation reserve program on water based recreation illustrates the potentially large biases that can result if the transfer is not calibrated

an analysis of under reporting for micro data sets the misreporting or double hurdle model abstract this paper analyzes under reporting through the two extended tobit models p tobit and double hurdle models the empirical results clarify the characteristics of under reporting misreporting plays an important role in under reporting

spending on alcohol evidence from the family expenditure survey 1970 1983 this paper reports on the investigation of a model of the determination of the share of household expenditure on alcohol using fes data for the united kingdom 1970 83 i e a time series of cross sections the authors pay special attention to the occurrence of zero expenditure variations in characteristics across the population and the modeling and interpretation of the stochastic term this term is modeled using the gamma distribution replacing the normal in tobit estimated parameters indicate strong positive skewness interactions between household characteristics and expenditure propensities are important copyright 1990 by royal economic society

calculating marginal effects in models for zero expenditures in household budgets using a heckman type correction using the heckamn approach either in single equation or multi equation settings general expressions are derived for calculating marginal effects and elasticities in the conventional calculation of marginal effects terms related to the change in the inverse of mills ratio are omitted using data from the 19877 88 nationwide food consumption survey we calculate income and household size elasticities for 12 food commodities we compare the magnitudes and signs of the elasticities using the conventional expressions of marginal effects and our derived expressions bottomline sizeable differences especially in single equation applications can occur in calculating marginal effects if one fails to account for changes in the inverse of the mills ratio

water for life the impact of the privatization of water services on child mortality while most countries are committed to increasing access to safe water and thereby reducing child mortality there is little consensus on how to actually improve water services one important proposal under discussion is whether to privatize water provision in the 1990s argentina embarked on one of the largest privatization campaigns in the world including the privatization of local water companies covering approximately 30 percent of the country s municipalities using the variation in ownership of water provision across time and space generated by the privatization process we find that child mortality fell 8 percent in the areas that privatized their water services and that the effect was largest 26 percent in the poorest areas we check the robustness of these estimates using cause specific mortality while privatization is associated with significant reductions in deaths from infectious and parasitic diseases it is uncorrelated with deaths from causes unrelated to water conditions

statistical models for zero expenditures in household budgets household budget surveys are an important source of data on consumer s expenditure not just for individual consumers but also for estimating national aggregates however it is a widespread finding that for certain commodities most notably tobacco and alcohol the estimate from the household survey falls short of the known consumption total calculated with some confidence from data on production imports exports and excise duties for example in the british family expenditure survey with which we shall largely be concerned total tobacco expenditure was underestimated in 1976 by 21 percent see kemsley redpath and holmes 1980 p 51 much of this understatement together with that on alcohol is thought to occur because of the design of the survey which excludes many persons amongst whom consumption of such items is thought to be atypically high e g prisoners hoteliers and their residents merchant seamen even so the possibility remains that some of the understatement is due to various types of misreporting by households included in the survey in this paper we consider a model in which the standard tobit specification tobin 1958 is supplemented by the operation of a simple binary censor the tobit model is essentially a linear regression model in which non positive observations of the dependent variable are replaced by zero we take this specification as our starting point but add a second censoring process that randomly replaces a fraction of the observations generated by the tobit model bv zeroes the combined model can serve as a representation of several types of

the demand for alcoholic beverages in spain the objective of this study is to analyze the main determinants of alcoholic beverages consumption at home data comes from the latest spanish household national survey which provides information on expenditure and quantities of different food products by household because households are interviewed only 1 week a large number of zeros have been recorded among the existing censured demand models the double hurdle dh model the purchase infrequency model and the tobit purchase infrequency model among others and after carrying out model selection tests the dh model has been finally estimated all expenditure elasticities are positive corresponding the highest value to spirits own price elasticities are negative and also in this case the spirits exhibit the highest value socio economic variables also play an important role in explaining consumer purchase and consumption decisions

distinguishing between market participation and infrequency of purchase models of butter demand household butter expenditures are modeled by market participation and infrequency of purchase specifications the market participation model assumes that zero expenditures represent either traditional corner solutions or consumers who never use the product whereas the infrequency of purchase model assumes that zero expenditures represent either corner solutions or consumption out of storage we determine that the infrequency of purchase specification is preferred to the market participation model by applying a nonnested test based upon likelihood functions if household expenditure surveys contained information about participation and frequency of purchase a likelihood function which contained both models could be written and estimated

private sector participation and performance of urban water utilities in china abstractin the early 1990s china began opening its urban water sector to nonstate capital to meet increasing urban water demand by 2007 more than 30 of large and medium urban water utilities had attracted private sector participation psp of which two thirds have a majority of nonstate shareholders to understand the factors that drive psp in urban water supply and to answer the key policy question of how psp has affected water utility performance we assemble and analyze a unique data set consisting of 208 urban water utilities servicing more than 300 million urban residents from 1998 to 2007 we find that a utility s profitability and liability level and a host city s road infrastructure in the prior year play important roles in driving private investors both to enter and to withdraw from the sector it is further found that psp utilities and mainly those with majority nonstate shareholders have made substantial cost savings through employment downsizing and cutting managerial expenses which le

the trade off between supervision and wages evidence of efficiency wages from the nlsy standard efficiency wage models suggest that workers employed in places with lower probabilities of identifying shirking will earn more as will workers who have better alternative opportunities this paper provides new empirical evidence in support of efficiency wage theory using the national longitudinal surveys of youth data the empirical results support the prediction of the model that workers employed in larger work groups are paid more a finding consistent with a supervision wage trade off additional evidence supports the prediction that workers with better alternative opportunities earn more the classical competitive theories of wage determination predict that workers will be paid the value of their marginal product these theories suggest that after accounting for differences in working conditions there should be no variation in wages among homogeneous workers recent findings that industry affiliation and firm size affect wages suggest that part of the explanation of wage structure is missing these results call into question the view that industry wage differentials can plausibly be rationalized with textbook competitive models krueger and summers 1988 p 280 this paper follows the efficiency wage literature by assuming that one important determinant of wage differences is variation in employers ability to monitor workers efforts 2 this paper provides new empirical evidence in support of efficiency wage theory using data from the national longitudinal surveys of youth nlsy a data set that is noticeably absent from the efficiency wage literature efficiency wage models attempt to complete the explanation of wage structure by focusing

investment choice and asset allocation of italian households the discrete continuous approach financial and monetary policies are considered to be effective depending on the reaction of financial markets which are increasingly populated by households in this article from intertemporal settings i derive a financial almost ideal fai demand system and i estimate it by highlighting the determinants of both limited participation to financial markets and asset substitutability complementarity in the allocating stage finally the wealth elasticities provide some further insights on the low diffusion of the newer and more complex financial instruments across italian households

joint purchasing decisions a multivariate negative binomial approach the analysis of household purchasing decisions for understanding consumption behaviour has received much attention recently mainly because of the measurement error problems that appear when using expenditure data to approximate consumption this paper discusses some empirical regularities of the household purchasing behaviour based on information about the number of purchases a household has declared having done during the survey period the concern of this paper is two fold first to show how to recover purchase frequency data from the spanish budget survey 1990 1991 second to discuss some empirical regularities of the joint purchasing decisions based on multivariate negative binomial models

heterogeneous firms and the organization of production firms in the same industry exhibit systematic differences in the organization of production and the structure of employment entrepreneurial ability is the specific scarce input that limits the size of a firm this input must be allocated to two activities coordinating production and monitoring workers able entrepreneurs can convert calendar time into larger supplies of coordinating effort that enable them to assemble large firms greater ability implies a higher shadow price of time which increases the implicit costs of monitoring a dispersion of entrepreneurial abilities generates an equilibrium size distribution of firms differences in monitoring costs affect the choice of worker productivities the design of products and the organization of production the monitoring cost hypothesis advanced in this paper goes a long way in explaining the equilibrium of an industry containing heterogeneous firms that differ in size and behavior

an examination of the effect of ownership on the relative efficiency of public and private water utilities the behavior of privately and publicly owned water utilities is examined by estimating a generalized variable cost function containing the regular characteristics of the neoclassical cost function without requiring that cost minimization subject to market prices be imposed as a maintained hypothesis assuming that unobserved shadow prices reflect the regulatory environment of the water industry tests for cost minimization are obtained by deriving shadow prices as functions of market prices the empirical results provide evidence that public water utilities are more efficient than private utilities on average but are more widely dispersed between best and worst practice