the impact of spatial patterns in road traffic externalities on willingness to pay estimates studying traffic related externalities in the city of gent belgium we find little to no evidence that observed spatial dependencies in actual objective externality levels play a direct role in determining spatial dependencies in the willingness to pay wtp for changes in the city s mobility policy investigating alternative factors that can influence wtp estimates however reveals that higher stated subjective externality levels are positively correlated with higher wtp for reducing exposure to noise air and odor pollution our results suggest complex interactions between housing decisions perceived externality levels and wtp estimates thus allowing for subjective perceptions sorting behavior and patterns in individuals characteristics can result in wtp estimates that are not spatially correlated even though the underlying externalities are spatially correlated

spatial competition and vertical integration cement and concrete revisited reply in this review 1983 mark mcbride reconsiders the federal trade commission s ftc enforcement policy toward vertical mergers between cement and ready mix concrete firms in response to a significant increase in acquisitions of ready mix concrete firms by cement manufacturers during the 1960 s the ftc undertook a series of legal actions to block or dissolve the mergers the actions of the ftc constituted one of the most intensive efforts undertaken to date to challenge vertical mergers in a single industry mcbride p 1012 notes that the actions of the ftc provoked considerable debate concerning the motivation for the mergers both in the industry and in academe a significant number of articles were published advancing various reasons for the mergers in addition to the ftc s main contention that the mergers were motivated by a desire for captive markets it has been suggested that there were economies of integration or that the mergers were the outcome of an erroneous view of the potential benefits to foreclosure held by executives in the beleaguered cement industry 2 mcbride s 1983 paper offers another explanation for the mergers his argument is that vertical integration was undertaken to avoid rigid oligopolistic pricing in the cement industry 3 the empirical results presented by mcbride suggest that vertical integration was a significant factor in the decline of cement prices in the 1960 s the purpose of this comment is to point out some of the problems with mcbride s analysis in particular we show that the experimental design of his testing equation is faulty and does not offer a test of his hypothesis as a result mcbride s analysis does not provide convincing evidence on whether cement firms vertically integrated to avoid rigid oligopolistic pricing or if cement firms were merely reacting to prices that had already begun to decline our intent however is not to challenge mcbride s contention that vertical integration can provide lower prices to consumers rather we would argue that the evidence presented at the ftc hearings involving cement and ready mix concrete firms as well as mcbride s and others analyses illustrate the problems in discerning the motives for mergers 4

measuring the impacts of teachers ii teacher value added and student outcomes in adulthood abstract are teachers impacts on students test scores value added a good measure of their quality this question has sparked debate partly because of a lack of evidence on whether high value ad

willingness to pay for land preservation across states and jurisdictional scale implications for benefit transfer in stated preference valuation of farmland preservation respondents are often told that preservation will occur within various jurisdictional scales that is community or state but are not told the specific location of parcels the resultant availability of welfare estimates for different scales and regions provides numerous avenues for benefit transfer this paper provides a systematic assessment of transfer error contrasting different methods for the transfer of farmland preservation values across states and jurisdictional scales results drawn from multistate choice experiments suggest that the choice of across scale versus across state transfer method can have significant implications for transfer validity

does public insurance crowd out private insurance the cost of expanding public sector health programs depends critically on the extent to which public eligibility will cover just the uninsured or will crowd out existing private insurance coverage we estimate the extent of crowd out arising from the expansions of medicaid to pregnant women and children over the 1987 1992 period we estimate that approximately 50 percent of the increase in medicaid coverage was associated with a reduction in private insurance coverage this occurred largely because employees took up employer based insurance less frequently there is also some evidence that employers contributed less for insurance and that workers dropped coverage of dependents

vertically summing public good demand curves an empirical comparison of economic versus political jurisdictions fiscal equivalence for efficient provision of a public good requires perfect correspondence between political and economic jurisdictions however the spatial extent of the economic jurisdiction is an empirical question drawing on four survey based valuation studies we measure the relative public good benefit gradient as a function of residential location from six natural resource public goods the results indicate commonly used state political jurisdictions reflect an average of 13 of total benefits in the economic jurisdiction although with a logarithmic form for distance the upper confidence interval of state benefits can include 100 for some species

optimized quantity within distance models of spatial welfare heterogeneity abstract spatial welfare heterogeneity is frequently modeled within stated preference analysis as a function of discrete or continuous distance between households and affected resources a common example is distance decay analysis although distance based models such as these are easily estimated the ubiquity of this paradigm can lead to analyses that overlook other forms of analysis with equal or greater relevance this paper develops an alternative approach to spatial heterogeneity in stated preference willingness to pay wtp based on the quantity or area of an affected resource surrounding each respondent at an optimized distance band or radius with distance bands optimized using a grid search algorithm that maximizes model likelihood methods and results are illustrated using a choice experiment on riparian land restoration in maine usa the resulting quantity within distance model identifies systematic spatial patterns that are undetectable using distance based analysis and directly relevant for welfare analysis

the principle of minimum differentiation holds under sufficient heterogeneity the so called principle of minimum differentiation stated by hotelling has been challenged by many authors this paper restores the principle by showing that n firms locate at the center of the market and charge prices higher than the marginal cost of production when heterogeneity in consumers tastes is large enough

individualized geocoding in stated preference questionnaires implications for survey design and welfare estimation this paper evaluates the common practice of generic mapping in stated preference valuation in which identical policy area maps are shown to all respondents this is compared to a more information intensive alternative in which individualized maps identify the location of each respondent s home relative to policy effects the evaluation is grounded in a theoretical model clarifying the impact of individualized spatial information on preferences for non market outcomes the model is illustrated using an application of choice experiments to riparian restoration in coastal maine results characterize valuation contexts for which valid preference elicitation likely requires the provision of individualized spatial information

the effect of medicaid expansions for low income children on medicaid participation and private insurance coverage evidence from the sipp abstract we examine medicaid enrollment and private coverage loss following expansions of medicaid eligibility we attempt to replicate cutler and gruber s q j econ 111 1996 391 results using the survey of income and program participation sipp and find smaller rates of take up and little evidence of crowding out we find that some of the difference in results can be attributed to different samples and recall periods in the data sets used extending the previous literature we find that take up is slightly increased if a child s siblings are eligible and with time spent eligible focusing on children whose eligibility status changes during the sample we estimate smaller take up effects we find little evidence of crowding out in any of our extensions

enhancing the content validity of stated preference valuation the structure and function of ecological indicators stated preference surveys often provide ambiguous descriptions of ecological commodities yielding welfare estimates that have unclear interpretations and cannot be linked to measurable outcomes this paper proposes guidelines to promote ecological content validity in survey scenarios and defensible use of ecological information for welfare analysis these guidelines are illustrated through an application to migratory fish restoration content validity is evaluated vis a vis norms for communication of ecological changes in the ecological literature findings suggest that less structured treatment of ecological commodities may lead to an omission of information that is relevant to respondents and essential for valid welfare estimation

effect of distance on the preservation value of water quality in the past dozen years an extensive body of literature has developed on the willingness to pay for water quality in particular its recreation use and nonuse preservation values this paper illustrates a procedure for estimating the effect of distance on the preservation value of environmental quality using the contingent valuation approach the case considered is the potential degradation of water quality due to coal mining activity in the flathead river drainage system montana the analysis supports a negative association for this particular study area the effect of distance on preservation value was considered both directly and indirectly through its effect on visits 36 references 2 tables

modeling spatial patchiness and hot spots in stated preference willingness to pay stated preference analyses often impose strong assumptions regarding spatial welfare distributions that can influence the validity of welfare analysis and aggregation these include spatial homogeneity and continuous distance decay global assumptions such as these are increasingly questioned by non economics disciplines in favor of approaches that allow for local patchiness drawing from this literature this article proposes methods to identify and evaluate hot spots in stated preference welfare estimates using local indicators of spatial association methods are illustrated using geocoded choice experiment data addressing river restoration results suggest the presence of statistically significant non continuous patterns overlooked by current approaches

the aggregation of environmental benefit values welfare measures distance decay and total wtp abstract we review the literature regarding the aggregation of benefit value estimates for non market goods two case studies are presented through which we develop an approach to aggregation which applies the spatial analytic capabilities of a geographical information system to combine geo referenced physical census and survey data to estimate a spatially sensitive valuation function these case studies show that the common reliance upon political rather than economic jurisdictions and the use of sample mean values within the aggregation process are liable to lead to significant errors in resultant values we also highlight the fact that for resources with use values then we should expect overall values to reduce with increasing distance from such sites but that changes in the choice of welfare measure will determine whether such distance decay is to be expected within values stated by those who are presently non users the paper concludes by providing recommendations for future improvements to the methodology

the effect of distance on willingness to pay values a case study of wetlands and salmon in california most contingent valuation studies in the literature utilized a pre determined geographic market area for their sample frame in other words they did not include variables that would measure the extent of the geographic areas over which to aggregate willingness to pay these studies implicitly assumed that the effects of geographic distance were moot an assumption that could have led to an understatement of the aggregate benefit values computed in these studies the overall goal of this study was to determine if distance affects willingness to pay for public goods with large non use values the data used came from a contingent valuation study regarding the san joaquin valley ca respondents were asked about their willingness to pay wtp for three proposed programs designed to reduce various environmental problems in the valley a logit model was used to examine the effects of geographic distance on respondents willingness to pay for each of the three programs results indicate that distance affected wtp for two of the three programs wetlands habitat and wildlife and the wildlife contamination control programs we calculate the underestimate in benefits if the geographic extent of the public good market is arbitrarily limited to one political jurisdiction

does ownership always matter abstract the objective of this paper is to explain and illustrate the complex relationship between ownership arrangements and enterprise performance it is commonly argued that efficiency will be lower in the public sector than the private because enterprise objectives deviate from maximisation of profits and because monitoring arrangements are inadequate due to the absence of capital market discipline we argue that public ownership does make the owner manager relationship more complicated because the chain of principals and agents is expanded objectives are politically determined and these are conveyed by a policy making administrative structure to management but the relative efficiency of public as against private ownership actually depends on the efficacy of capital market monitoring on the political and constitutional system on the information and sanctions available to policy makers and on the nature of the management market variation in these factors can help to explain the different natures and roles of the public sector between countries

the impact of medicaid on labor market activity and program participation evidence from the oregon health insurance experiment united states dept of health and human services assistant secretary for planning and evaluation

early life health interventions and academic achievement this paper studies the effect of improved early life health care on mortality and long run academic achievement in school we use the idea that medical treatments often follow rules of thumb for assigning care to patients such as the classification of very low birth weight vlbw which assigns infants special care at a specific birth weight cutoff using detailed administrative data on schooling and birth records from chile and norway we establish that children who receive extra medical care at birth have lower mortality rates and higher test scores and grades in school these gains are in the order of 0 15 0 22 standard deviations

using differences in knowledge across neighborhoods to uncover the impacts of the eitc on earnings we develop a new method of estimating the impacts of tax policies that uses areas with little knowledge about the policy s marginal incentives as counterfactuals for behavior in the absence of the policy we apply this method to characterize the impacts of the earned income tax credit eitc on earnings using administrative tax records covering all eitc eligible lers from 19962009 we begin by developing a proxy for local knowledge about the eitc schedule the degree of sharp bunching at the exact income level that maximizes eitc refunds by individuals who report self employment income the degree of self employed sharp bunching varies signi cantly

spatial competition and spatial price discrimination the analysis of spatial competition under conditions of free entry which derives its major impetus from the seminal work of losch 1954 has been conducted in general on the assumption that the competitive firm will adopt an f o b pricing scheme see for example capozza and van order 1978 and holahan 1978 greenhut 1956 does consider some of the implications of discriminatory pricing within competitive markets but his analysis adopts an essentially short run view and provides little rationale for the choice of such a pricing policy by competitive firms this is in contrast with developments in the analysis of spatial monopoly the early work of singer 1937 and hoover 1937 and subsequent developments by for example greenhut 1956 beckmann 1976 beckmann and ingene 1976 greenhut and greenhut 1977 holahan 1975 and norman 1977 indicate that the spatial monopolist should adopt a discriminatory spatial pricing policy where spatial price discrimination is taken conventionally to mean that delivered prices do not follow an f o b scheme but that all concumers equidistant from a particular supplier pay the same price it is rarely however that the results generated by the analysis of spatial monopoly are reconsidered in the analysis of spatial competition in particular although we know that spatial price discrimination will in general increase a monopolist s profit the assumption that profit maximising spatially competitive firms will adopt f o b pricing schemes has rarely been questioned and has not been questioned within the loschian competitive framework greenhut and ohta 1975a chapter 8 and chapter 8 appendix i are notable exceptions but in both cases they depart from the loschian scheme the first objective of this paper is therefore to show that when loschian competitive firms are allowed the option of discriminatory pricing i e are free of institutional constraints which require f o b pricing they will be forced to exercise that option in order to maintain normal profits secondly we shall show that if competitive conditions change the form of price discrimination will also change and that under certain competitive conditions the degree of discrimination will increase with the degree of competition leading eventually to uniform pricing thirdly we compare two competitive cases with multi plant monopoly and derive the spatial analogue of the conventional spaceless monopoly perfect competition comparison the monopolist s plants will be larger in area and total output than each competitive firm but will supply less per consumer at a higher average price welfare comparisons are less clear cut in that they are dependent upon the type of competition we assume we show however that welfare maximisation requires marginal cost pricing where marginal cost includes transport costs and so requires f o b pricing if there are economies of scale to production it follows that welfare maximisation will require production subsidy

willingness to pay for agricultural land preservation and policy process attributes does the method matter this article examines relationships between willingness to pay for land preservation and policy process attributes the approach departs from traditional welfare assessments in that it does not constrain attributes of the policy process to be utility neutral results indicate policy process attributes may influence utility in some circumstances even after controlling for the influence of land use outcomes often correlated with specific policy techniques results further imply that in some cases even comprehensive specification of land use outcomes by stated preference instruments may be insufficient to prevent systematic shifts in willingness to pay related to unspecified yet assumed policy process attributes

enhanced geospatial validity for meta analysis and environmental benefit transfer an application to water quality improvements meta regression models are commonly used within benefit transfer to estimate willingness to pay wtp for environmental quality improvements theory suggests that these estimates should be sensitive to geospatial factors including resource scale market extent and the availability of substitutes and complements valuation meta regression models addressing the quantity of non market commodities sometimes incorporate spatial variables that proxy for a subset of these effects however meta analyses of wtp for environmental quality generally omit geospatial factors such as these leading to benefit transfers that are invariant to these factors this paper reports on a meta regression model for water quality benefit transfer that incorporates spatially explicit factors predicted by theory to influence wtp the metadata are drawn from stated preference studies that estimate per household wtp for water quality changes in united states water bodies and combine primary study information with extensive geospatial data from external sources results find that geospatial variables are associated with significant wtp variations as predicted by theory and that inclusion of these variables reduces transfer errors

indices of biotic integrity in stated preference valuation of aquatic ecosystem services stated preference surveys often give minimal attention to distinctions between intermediate and final ecosystem services leading to the potential for welfare estimates that overlook misrepresent or double count associated values this paper illustrates potential mechanisms through which multimetric indexes of the type developed in the ecological literature here an index of biotic integrity can be used within stated preference survey scenarios to both improve the validity of survey responses and provide otherwise unavailable information on willingness to pay for intermediate and final ecosystem services we illustrate the approach using a choice experiment application to the restoration of migratory fish in a rhode island watershed where assumptions of the model hold results can allow transparent disentanglement and estimation of marginal values for both intermediate and final ecosystem services

non users willingness to pay for a national park an application and critique of the contingent valuation method bateman i j and langford i h 1997 non users willingness to pay for a national park an application and critique of the contingent valuation method reg studies 31 571 582 a great deal of the ongoing academic debate concerning the contingent valuation cv method has focused upon whether or not the method is suitable for assessing non use values this paper presents results from a study examining non users values for preserving the norfolk broads a wetland area of recognized international importance from the threat of saline flooding discussion of results centres upon the validity of the cv method for eliciting unbiased estimates of non use value a graphical representation of findings from a variety of studies is presented to suggest that such results are logically ordered across goods and valuation scenarios however as the paper concludes logicality and validity are not necessarily synonymous bateman i j et langford i h 1997 la volonte des non usagers de payer les parcs nationaux

employment hysteresis from the great recession this paper uses us local areas as a laboratory to test for long term impacts of the great recession in administrative longitudinal data i estimate that exposure to a 1 percentage point larger 200

state abortion rates the impact of policies providers politics demographics and economic environment abstract this paper uses data on abortion rates by state from 1974 1988 to estimate two stage least squares models with fixed state and year effects restrictions on medicaid funding for abortion are correlated with lower abortion rates in state and higher rates among nearby states a maximal estimate suggests that 19 25 of the abortions among low income women that are publicly funded do not take place after funding is eliminated parental notification laws for teen abortions do not significantly affect aggregate abortion rates a larger number of abortion providers in a state increases the abortion rate primarily through inducing cross state travel

health insurance and mortality experimental evidence from taxpayer outreach we evaluate a randomized pilot study in which the irs sent informational letters to 3 9 million taxpayers who paid a tax penalty for lacking health insurance coverage under the affordable care act drawing on administrative data we study the effect of the intervention on taxpayers subsequent health insurance enrollment and mortality we find the intervention led to increased coverage in the two years following treatment and that this additional coverage reduced mortality among middle aged adults over the same time period our results provide the first experimental evidence that health insurance reduces mortality

cournot competition yields spatial agglomeration most theoretical models of spatial competition show a strong tendency toward spatial dispersion of firms yet common observations suggest that firms tend to agglomerate in this paper the authors show that competition between cournot type oligopolists that discriminate over space leads to spatial agglomeration one implication is that firms do not necessarily earn supernormal profits at the free entry equilibrium copyright 1991 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

the oregon health insurance experiment evidence from the first year in 2008 a group of uninsured low income adults in oregon was selected by lottery to be given the chance to apply for medicaid this lottery provides an opportunity to gauge the effects of expanding access to public health insurance on the health care use financial strain and health of low income adults using a randomized controlled design in the year after random assignment the treatment group selected by the lottery was about 25 percentage points more likely to have insurance than the control group that was not selected we find that in this first year the treatment group had substantively and statistically significantly higher health care utilization including primary and preventive care as well as hospitalizations lower out of pocket medical expenditures and medical debt including fewer bills sent to collection and better self reported physical and mental health than the control group

the long run impact of cash transfers to poor families lleras muney we estimate the long run impact of cash transfers to poor families on children s longevity educational attainment nutritional status and income in adulthood to do so we collected individual level administrative records of applicants to the mothers pension program the first government sponsored welfare program in the united states 1911 1935 and matched them to census wwii and death records male children of accepted applicants lived one year longer than those of rejected mothers they also obtained onethird more years of schooling were less likely to be underweight and had higher income in adulthood than children of rejected mothers jel i12 i14 i18 i32 i38 j16 n32

the effects of exposure to better neighborhoods on children new evidence from the moving to opportunity experiment the moving to opportunity mto experiment offered randomly selected families housing vouchers to move from high poverty housing projects to lower poverty neighborhoods we analyze mto s impacts on children s long term outcomes using tax data we find that moving to a lower poverty neighborhood when young before age 13 increases college attendance and earnings and reduces single parenthood rates moving as an adolescent has slightly negative impacts perhaps because of disruption effects the decline in the gains from moving with the age when children move suggests that the duration of exposure to better environments during childhood is an important determinant of children s long term outcomes jel i31 i38 j13 r23 r38

how does your kindergarten classroom affect your earnings evidence from project star in project star 11 571 students in tennessee and their teachers were randomly assigned to classrooms within their schools from kindergarten to third grade this article evaluates the long term impacts of star by linking the experimental data to administrative records we first demonstrate that kindergarten test scores are highly correlated with outcomes such as earnings at age 27 college attendance home ownership and retirement savings we then document four sets of experimental impacts first students in small classes are significantly more likely to attend college and exhibit improvements on other outcomes class size does not have a significant effect on earnings at age 27 but this effect is imprecisely estimated second students who had a more experienced teacher in kindergarten have higher earnings third an analysis of variance reveals significant classroom effects on earnings students who were randomly assigned to higher quality classrooms in grades k 3 as measured by classmates end of class test scores have higher earnings college attendance rates and other outcomes finally the effects of class quality fade out on test scores in later grades but gains in noncognitive measures persist

substitution effects and spatial preference heterogeneity in single and multiple site choice experiments a novel discrete choice experiment dce design allows testing of substitution effects based on the framing of and distances to substitute sites the same ecosystem services and biodiversity provided at different sites are valued independently in single site dces and simultaneously in a multiple site dce using an identical experimental design site specific utility functions are estimated with and without controlling for spatial preference heterogeneity framing choices as alternative projects at single or multiple sites significantly influences substitutability between sites choice behavior and welfare estimates distance decay displays significant heterogeneity in different directions from the valued sites and between urban and rural areas

a unified welfare analysis of government policies we conduct a comparative welfare analysis of 133 historical policy changes over the past half century in the united states focusing on policies in social insurance education and job training taxes and cash transfers and in kind transfers for each policy we use existing causal estimates to calculate both the benefit that each policy provides its recipients measured as their willingness to pay and the policy s net cost inclusive of long term impacts on the government s budget we divide the willingness to pay by the net cost to the government to form each policy s marginal value of public funds or its mvpf comparing mvpfs across policies provides a unified method of assessing their impact on social welfare our results suggest that direct investments in low income children s health and education have historically had the highest mvpfs on average exceeding 5 many such policies have paid for themselves as governments recouped the cost of their initial expenditures through additional taxes collected and reduced transfers we find large mvpfs for education and health policies amongst children of all ages rather than observing diminishing marginal returns throughout childhood we find smaller mvpfs for policies targeting adults generally between 0 5 and 2 expenditures on adults have exceeded this mvpf range in particular if they induced large spillovers on children we relate our estimates to existing theories of optimal government policy and we discuss how the mvpf provides lessons for the design of future research

long run impacts of childhood access to the safety net a growing economics literature establishes a causal link between in utero shocks and health and human capital in adulthood most studies rely on extreme negative shocks such as famine and pandemics we are the first to examine the impact of a positive and policy driven change in economic resources available in utero and during childhood in particular we focus on the introduction of a key element of the u s safety net the food stamp program which was rolled out across counties in the u s between 1961 and 1975 we use the panel study of income dynamics to assemble unique data linking family background and county of residence in early childhood to adult health and economic outcomes the identification comes from variation across counties and over birth cohorts in availability of the food stamp program our findings indicate that the food stamp program has effects decades after initial exposure specifically access to food stamps in childhood leads to a significant reduction in the incidence of metabolic syndrome obesity high blood pressure and diabetes and for women an increase in economic self sufficiency overall our results suggest substantial internal and external benefits of the safety net that have not previously been quantified

long term impacts of childhood medicaid expansions on outcomes in adulthood we use administrative data from the internal revenue service to examine long term impacts of childhood medicaid eligibility expansions on outcomes in adulthood at each age from 19 to 28 greater medicaid eligibility increases college enrolment and decreases fertility especially through age 21 starting at age 23 females have higher contemporaneous wage income although male increases are imprecise together both genders have lower mortality these adults collect less from the earned income tax credit and pay more in taxes cumulatively from ages 19 to 28 at a 3 discount rate the federal government recoups 58 cents of each dollar of its investment in childhood medicaid

worms at work long run impacts of a child health investment this study estimates long run impacts of a child health investment exploiting community wide experimental variation in school based deworming the program increased labor supply among men and education among women with accompanying shifts in labor market specialization ten years after deworming treatment men who were eligible as boys stay enrolled for more years of primary school work 17 more hours each week spend more time in nonagricultural self employment are more likely to hold manufacturing jobs and miss one fewer meal per week women who were in treatment schools as girls are approximately one quarter more likely to have attended secondary school halving the gender gap they reallocate time from traditional agriculture into cash crops and nonagricultural self employment we estimate a conservative annualized financial internal rate of return to deworming of 32 and show that mass deworming may generate more in future government revenue than it costs in subsidies

how people respond to contingent valuation questions a verbal protocol analysis of willingness to pay for an environmental regulation abstract this paper investigates what a respondent is thinking when answering a willingness to pay question in a contingent valuation using a think aloud technique from psychology called verbal protocol analysis the willingness to pay responses we observed seem to be constructed from a variety of considerations including an obligation to pay a fair share of the cost of the solution and signaling concern for a larger set of environmental issues the finding that respondents seem to construct their values at the time they are asked rather than reporting a more well defined value is seen as consistent with over two decades of research on the psychology of decision making potential uses of verbal protocols in contingent valuation studies are also discussed

directional heterogeneity in wtp models for environmental valuation many studies in the stated preference literature on environmental valuation do not include the effects of substitutes and distance in willingness to pay wtp models in spite of the relevance of these effects in aggregation and benefit transfer heterogeneity in the availability of substitutes over space may cause multidirectional distance effects in wtp as a result disregarding this spatial heterogeneity may lead to biased estimators of the distance effect and associated wtp values cameron 2006 in this paper we demonstrate that distance decay is subject to significant directional effects which tend to be related to differences in the availability of substitutes across the study area we apply a straightforward methodology to account for such spatial heterogeneity in choice experiments and assess the effect on wtp for improvements in ecosystem services in a lake district we model distance decay effects whilst controlling for heterogeneity between users and non users and non use related wtp reasons the directional effects result in significantly different wtp estimates different market sizes reflecting the population with positive wtp and differences in total wtp up to 32

bounding causal effects using data from a contaminated natural experiment analysing the effects of teenage childbearing in this paper we consider what can be learned about causal effects when one uses a contaminated instrumental variable in particular we consider what inferences can be made about the causal effect of teenage childbearing on a teen mother s subsequent outcomes when we use the natural experiment of miscarriages to form an instrumental variable for teen births miscarriages might not meet all of the conditions required for an instrumental variable to identify such causal effects for all of the observations in our sample however it is an appropriate instrumental variable for some women namely those pregnant women who experience a random miscarriage although information from typical data sources does not allow one to identify these women we show that one can adapt results from horowitz and manski 1995 on identification with data from contaminated samples to construct informative bounds on the causal effect of teenage childbearing we use these bounds to re examine the effects of early chilbearing on the teen mother s subsequent educational and labour market attainment as considered in hotz mcelroy and sanders 1995a 1995b consistent with their study these bounds indicate that women who have births as teens have higher labour market earnings and hours worked compared to what they would have attained if their childbearing had been delayed

mixed oligopoly and spatial agglomeration a comment this paper extends matsushima and matsumura 2003 by incorporating a large production cost difference between public and private firms in a quantity setting spatial mixed oligopoly the public and private firms first choose their locations in a linear market and then compete in quantities it is shown that for a significant inefficiency of the public firm all firms including both public and private firms agglomerate at the market centre ce texte developpe les resultats de matsushima et matsumura 2003 en incorporant la possibilite d une grande difference de couts de production entre l entreprise publique et les entreprises privees dans un oligopole spatial mixte de concurrence par les quantites les entreprises publiques et privees choisissent leur localisation dans un marche lineaire et se concurrencent par les quantites on montre que s il existe une inefficacite significative de l entreprise publique toutes les entreprises publiques et privees tendent a s agglomerer au centre du marche

the effect of child health insurance access on schooling evidence from public insurance expansions although a sizable literature analyzes the effects of public health insurance programs on short run health outcomes little prior work has examined their long term effects we examine the effects of public insurance expansions among children in the 1980s and 1990s on their future educational attainment we find that expanding health insurance coverage for low income children increases the rate of high school and college completion these estimates are robust to only using federal medicaid expansions and mostly are due to expansions that occur when the children are not newborns our results indicate that the long run benefits of public health insurance are substantial

spatial preference heterogeneity in forest recreation abstract in this study we analyze the preferences for recreational use of forests in lorraine northeastern france applying stated preference data our approach allows us to estimate individual specific preferences for recreational use of different forest types these estimates are used in a second stage of the analysis where we test whether preferences depend on access to recreation sites we find that there is significant preference heterogeneity with respect to most forest attributes the spatial analysis shows that preferences for forests with parking and picnic facilities are correlated with having access to such forests while for the other attributes considered dominant tree species trekking paths and presence of lake and rivers we find no correlation between stated preferences and accessibility this implies that the problem of endogenous distances in the travel cost method parsons 1991 may be present in the estimation of welfare economic values for parking and picnic facilities in the analyzed model the results underline the importance of considering spatial heterogeneity of preferences carrying out economic valuation of spatial delineated environmental goods and that the spatial variation in willingness to pay for such goods is not only explained by the users transport costs of accessing the sites

will extending medicaid to two parent families encourage marriage several welfare programs in the united states restrict eligibility to single parent families this paper asks whether eliminating this restriction for medicaid encourages marriage i identify medicaid s effect through a series of health insurance reforms that were passed in the 1980s and 1990s targeting young children these reforms were associated with an increase in the probability of marriage of 1 7 percentage points while the expansions offered some incentives to become married they also created other incentives to become divorced known as the independence effect after controlling for the outflows from marriage due to the independence effect the estimated effect increases by 10 percent

does welfare inhibit success the long term effects of removing low income youth from the disability rolls i estimate the effects of removing low income youth with disabilities from supplemental security income ssi on their earnings and income in adulthood using a regression discontinuity design based on a 1996 policy change in age 18 medical reviews i find that youth who are removed from ssi at age 18 recover one third of the lost ssi cash income in earnings ssi youth who are removed and stay off ssi earn on average 4 400 annually and they lose 76 000 in present discounted observed income over the 16 years following removal relative to those who do not receive a review jel i30 i38 j14 supporters of welfare programs defend them as vital lifelines for those who face barriers to work while critics charge that these programs create perverse incentives to qualify and perpetuate dependency encapsulating this debate is the controversy over the us supplemental security income ssi program a program that provides cash payments and medicaid eligibility to low income children and adults with disabilities and the aged elderly after three decades of rapid expansion ssi is now the largest nonwork based cash welfare program in the united states paying about 50 billion each year to 8 million recipients including 1 3 million children 1 ssi has been singled out by policymakers and the media for potential perverse incentives

what to value and how ecological indicator choices in stated preference valuation the ecological literature accepts that many policy outcomes cannot be observed directly and must be characterized using indicators multiple indicators can often be used to communicate similar ecological outcomes previous studies using alternative indicators in stated preference surveys suggest that welfare estimates may be indicator dependent casting doubt on whether welfare estimates are sufficiently reliable for cost benefit analysis we suggest that the reason for such indicator dependence may be that indicators used in these prior studies represented different outcomes valued by respondents this possibility underscores the need for greater attention to selection of indicators and their properties within stated preference survey design this paper develops a model introducing the concept of outcome equivalent indicators defined as indicators that provide alternative representations of identical underlying outcomes to assess empirically whether welfare estimates are indeed robust to indicator choice when alternative indicators are expected to be outcome equivalent we analyze data from a choice experiment estimating willingness to pay for migratory fish restoration in rhode island usa results demonstrate that welfare estimates are robust to the use of alternative ecological indicators within stated preference scenarios

mixed oligopoly and spatial agglomeration abstract we investigate a mixed market where a state owned welfare maximizing public firm competes against profit maximizing private firms we use a circular city model with quantity setting competition in contrast to a pure market case discussed by pal 1998a spatial agglomeration of private firms always appears in equilibrium all private firms locate at the same point and the public firm locates at the opposite side we also find that this equilibrium pattern of the location is second best provided that output of each private firm cannot be controlled by the social planner jel classification h42 l13 oligopole mixte et agglomeration spatiale les auteurs examinent un marche mixte ou une entreprise publique possedee par l etat et cherchant a maximiser le niveau de bien etre est en concurrence avec des entreprises privees qui cherchent a maximiser leurs profits on utilise un modele de cite circulaire ou la concurrence se fait en choisissant la quantite produite en contraste avec le cas du marche parfait discute par pal 1998a l agglomeration spatiale des entreprises privees parait etre en equilibre toutes les entreprises privees se localisent au meme point et l entreprise publique se localise du cote oppose il appert que ce pattern d equilibre de localisation est un equilibre de second ordre compte tenu du fait que la production de chaque entreprise privee ne peut etre controlee par le planificateur social

health insurance eligibility utilization of medical care and child health two economists applied data from the current population survey and the national health interview survey and state level data on child mortality to a simulation model of utilization of medical care that varies only with the states legislative environment to examine the utilization of medical care and health effects of medicaid eligibility on low income children the models took into consideration the recent expansions of medicaid to low income children 38 of those ineligible for medicaid in 1984 who became eligible due to changes during 1984 1992 were uninsured between 1984 and 1992 expansions of the medicaid program increased the proportion of children eligible for medicaid almost two fold 16 1 vs 31 2 yet coverage rates were always lower than eligibility rates 13 2 vs 16 1 in 1984 and 20 3 vs 31 2 in 1992 and the increase in coverage rates was only about 50 of the increase in eligibility rates during 1984 1992 the probability that a child was eligible for medicaid increased the probability of health insurance coverage by 29 77 when the model considered bias in variables e g a recession in a state the take up rate was only 22 73 nevertheless medicaid markedly increased use of medical care for example eligibility for medicaid increased the likelihood of making a visit to a physicians office in the last two weeks by about 50 it also increased the probability of a child visiting the hospital suggesting inefficiency in the way that providers deliver care to medicaid enrollees medicaid eligibility had a significant effect on reducing child mortality the 15 1 percentage point increase in eligibility during 1984 1992 reduced child mortality by 4 5 when the researchers examined parent assessed subjective health measures medicaid eligibility had no effect on child health medicaid eligibility reduced race and education based disparities in the number of visits and racial differences in mortality yet it may actually intensify current disparities in health care delivery site