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Demonstrating bias and improved inference for stoves’ health benefits

Valerie Mueller, Alexander Pfaff, John Peabody, Yaping Liu, Kirk R. Smith
International Journal of Epidemiology (2011) 1–9 [doi:10.1093/ije/dyr150]

PDF link iconBACKGROUND: Many studies associate health risks with household air pollution from biomass fuels and stoves. Evaluations of stove improvements can suffer from bias because they rarely address health-relevant differences between the households who get improvements and those who do not. METHODS: We demonstrate both the potential for bias and an option for improved stove inference by applying to household air pollution a technique used elsewhere in epidemiology, propensity-score matching (PSM), based on a stoves-and-health survey for China (15 counties, 3500 households). RESULTS: Health-relevant factors (age, wealth, kitchen ventilation) do in fact differ considerably between the households with stove improvements and those without. We study the resulting bias in estimates of cleaner-stove impacts using a self-reported Physical Component Summary (PCS). Typical stoves-literature regressions with little control for non-stove factors suggest no benefits from a cleaner-fuel stove relative to a traditional biomass stove. Yet increasing controls raises the impact estimates. Our PSM estimates address the differences in health-relevant factors using ‘apples to apples’ comparisons between those with improved stoves and ‘similar’ households. This generates higher estimates of clean-stove benefits, which are on the order of one half the standard deviation of the PCS outcome. CONCLUSIONS: Our data demonstrate the potential importance of bias in household air pollution studies. This results from failure to address the possibility that those receiving improved stoves are themselves prone to better or worse health outcomes. It suggests the value of data collection and of study design for cookstove interventions and, more generally, for policy interventions within many health outcomes.


Efficiency and equity in negotiated resource transfers: contributions and limitations of trust with limited contracts

Alexander Pfaff, Maria Alejandra Velez
Ecological Economics 74 (2012) 55–63

PDF link iconWe consider a case of water reallocation in Brazil, one which has numerous analogs elsewhere. To permit empirical study of the effects of institutions that can facilitate or restrict  allocations, we conducted field experiments to explore trust’s potential when resource contracts are limited, using a novel asymmetric-productivity ultimatum game with a final surplus-sharing step added. As a form of informal institution, trust could in principle make rights and contracts unnecessary. We observe whether trust in compensation is in fact expected and expressed. We also explore whether trust is exploited, and the effect of communication, within our two bargaining structures: (1) no communication; and (2) with a non-binding message concerning the surplus to be shared. We see that our participants both expect and express trust that some of the surplus will be shared. Trust raises total output and some surplus is indeed shared: those who trust gain a bit on average; and the more trust was shown, the more was shared. However, often the trust was barely repaid. Further, the messages—found to help in other research—had little impact and were often untrue. In sum, trust does matter but both efficiency and equity could well rise with complete contracts.


Assessing the impact of institutional design of Payments for Environmental Services: the Costa Rican experience

Juan Robalino, Alexander Pfaff, Laura Villalobos
B. Rapidel, F. DeClerk, J. LeCoq and J. Beer Eds. “Ecosystem services from Agriculture and Agroforestry: Measurement and Payment”. Chapter 14. Earthscan Press.

PDF link iconin Costa Rica. The first years of implementation set the basis for what the programme has become. Important changes have been made since the beginning, such as the institution in charge of implementing the programme, parcels selection criteria, and new offices that were opened in different areas of the country with the objective of reducing application costs. Using 2003 as the starting point of when these changes took place, we discuss if they had a programme efficiency effect on reducing deforestation. We focus on forest conservation contracts because it is the most important category of the programme in terms of budget and amount of land enrolled. We use matching techniques, geographic information systems (GIS), characterize the areas where payments were implemented in each of the time periods using a long list of variables, and look for similar areas that did not receive payments. We find that, as other studies have found for this period (Robalino et al, 2008; Arriagada, 2008), the impacts are low but significant. While it seems that, overall, institutional changes have not had a significant effect on impact, we also look at the impacts of forest conservation contracts per office. We find that those offices located in areas with high deforestation tend to have higher impacts.


Policy Impacts on Deforestation: Lessons Learned from Past Experiences to Inform New Initiatives

Alexander Pfaff, Erin O. Sills, Gregory S. Amacher, Michael J. Coren, Kathleen Lawlor, Charlotte Streck
Report from the Nicholas Institute for Environmental Policy Solutions, Duke University (with the support of the Packard Foundation)

PDF link iconNational and international efforts within the last few decades to reduce forest loss, while having some impact, have failed to substantially slow the loss of the world’s forests. Forest loss, i.e., deforestation and forest degradation, is widespread and accounts for 12%–17% of the world’s greenhouse gas (GHG) emissions. Global concern about climate change and the realization that reduced emissions from deforestation and degradation (REDD) can play a role in climate change mitigation make it critical to learn from our past experiences with policies to reduce forest loss. Within the UN Framework Convention on Climate Change (UNFCCC), negotiators are actively considering ways to include incentives for REDD and other forest carbon activities in any post-2012 treaty. In parallel, the U.S. Congress is developing proposals for a long-term climate policy that includes incentives for REDD, and possibly other international forest carbon activities. Such policies may mobilize new funds for forest conservation, including for addressing drivers of deforestation and forest degradation in developing countries. Climate-related incentives for REDD are likely to be performance-based, i.e., to emphasize the measurement, reporting, and verification of all results. The implementation of this emphasis, alongside the introduction of new financial incentives, could increase such policies’ impacts on forest loss relative to the past. Policy effectiveness, efficiency, and equity can increase if we learn lessons from the past about what drives and what inhibits deforestation and degradation. It is in the interest of any REDD program to understand what has worked in reducing deforestation and degradation and what has not, as well as the reasons for observed differences in outcomes. Investments and policies can then more effectively embrace and extend success while reducing risks of further failures. This report aims to provide lessons to inform U.S. and international policymakers by analyzing dominant influences on deforestation and degradation. We study not only forest-focused policies, but also other policies that directly or indirectly influence forest loss, all in light of relevant nonpolicy factors such as trends in commodity prices. We provide examples of previous policies to draw lessons from successes and failures, then link those observations about the past to the decisions current policymakers must soon make within ongoing climate policy deliberations.


Global protected area impacts

Lucas N. Joppa, Alexander Pfaff
Proceedings of the Royal Society B 2010 doi:10.1098/rspb.2010.1713

PDF link iconProtected areas (PAs) dominate conservation efforts. They will probably play a role in future climate policies too, as global payments may reward local reductions of loss of natural land cover. We estimate the impact of PAs on natural land cover within each of 147 countries by comparing outcomes inside PAs with outcomes outside. We use ‘matching’ (or ‘apples to apples’) for land characteristics to control for the fact that PAs very often are non-randomly distributed across their national landscapes. Protection tends towards land that, if unprotected, is less likely than average to be cleared. For 75 per cent of countries, we find protection does reduce conversion of natural land cover. However, for approximately 80 per cent of countries, our global results also confirm (following smaller-scale studies) that controlling for land characteristics reduces estimated impact by half or more. This shows the importance of  controlling for at least a few key land characteristics. Further, we show that impacts vary considerably within a country (i.e. across a landscape): protection achieves less on lands far from roads, far from cities and on steeper slopes. Thus, while planners are, of course, constrained by other conservation priorities and costs, they could target higher impacts to earn more global payments for reduced deforestation.


Regional Interdependence and Forest “Transitions”: substitute deforestation limits the relevance of local reversals

Alexander Pfaff, Robert Walker
Land Use Policy 2010 27:119–129

PDF link iconUsing case studies and concepts we suggest that constraints upon aggregate or global forest transition are significantly more severe than those upon local forest reversals. The basic reason is that one region’s reversal can be facilitated by other regions that supply resources and goods, reducing the demands upon the region where forests rise. Many past forest reversals involve such interdependence. For ‘facilitating regions’ also to rise in forest requires other changes, since they will not be receiving such help. We start by discussing forest-transitions analysis within the context of Environmental Kuznets Curves (EKCs), for a useful typology of possible shifts underlying transitions. We then consider the historical Northeast US where a regional reversal was dramatic and impressive. Yet this depended upon agricultural price shocks, due to the Midwest US supplying food, and also upon the availability of timber from other US regions. Next we consider deforestation in Amazônia, whose history (like the Northeast US) suggests a potential local role for urbanization, i.e. spatial concentration of population. Yet inter-regional issues again are crucial. For cattle and soy, expansion of global demands may give to Amazonia a role more like the Midwest than the Northeast US. In addition, across-region interdependencies will help determine where reversal and facilitation occur. Finally we discuss the constraints upon very broad forest transition.

Indigenous Lands, Protected Areas, and Slowing Climate Change

Taylor H. Ricketts, Britaldo Soares-Filho, Gustavo A.B. da Fonseca, Daniel Nepstad, Alexander Pfaff, Annie Petsonk, Anthony Anderson, Doug Boucher, Andrea Cattaneo, Marc Conte, Ken Creighton, Lawrence Linden, Claudio Maretti, Paulo Moutinho, Roger Ullman, Ray Victurine
PLoS Biol 2010 8(3): e1000331. doi:10.1371/journal.pbio.1000331

PDF link iconForest clearing and degradation account for roughly 15% of global greenhouse gas emissions, more than all the cars, trains, planes, ships, and trucks on earth. This is simply too big a piece of the problem to ignore; fail to reduce it and we will fail to stabilize our climate. Although the recent climate summit in Copenhagen failed to produce a legally binding treaty, the importance of forest conservation in mitigating climate change was a rare point of agreement between developed and developing countries and is emphasized in the resulting Copenhagen Accord. Language from the meeting calls for developing countries to reduce emissions from deforestation and degradation (nicknamed REDD), and for wealthy nations to compensate them for doing so. For REDD to succeed, forest nations must develop policies and institutions to reduce and eventually eliminate forest clearing and degradation. One of the most straightforward components of such a program is also one of the oldest and most reliable tricks in the conservation book: protected areas. Indigenous lands and other protected areas (hereafter ILPAs)— created to safeguard land rights, indigenous livelihoods, biodiversity, and other values— contain more than 312 billion tons of carbon (GtC). Crucially, and paradoxically, this ‘‘protected carbon’’ is not entirely protected. While ILPAs typically reduce rates of deforestation compared to surrounding areas, deforestation (with resulting greenhouse gas [GHG] emissions) often continues within them, especially inside those that lack sufficient funding, management capacity, or political backing. These facts suggest an attractive but overlooked opportunity to reduce GHG emissions: creating new ILPAs and strengthening existing ones. Here, we evaluate the case for this potential REDD strategy. We focus on the Amazon basin given its importance for global biodiversity, its enormous carbon stocks, and its advanced network of indigenous lands and other protected areas.

Reassessing the forest impacts of protection: The challenge of nonrandom location and a corrective method

Lucas Joppa, Alexander Pfaff
Ann. N.Y. Acad. Sci. 1185 (2010) 135–149

PDF link iconProtected areas are leading tools in efforts to slow global species loss and appear also to have a role in climate change policy. Understanding their impacts on deforestation informs environmental policies. We review several approaches to evaluating protection’s impact on deforestation, given three hurdles to empirical evaluation, and note that “matching” techniques fromeconomic impact evaluation address those hurdles. The central hurdle derives from the fact that protected areas are distributed nonrandomly across landscapes.Nonrandom location can be intentional, and for good reasons, including biological and political ones. Yet even so, when protected areas are biased in their locations toward less-threatened areas, many methods for impact evaluationwill overestimate protection’s effect. The use ofmatching techniques allows one to control for known landscape biases when inferring the impact of protection. Applications of matching have revealed considerably lower impact estimates of forest protection than produced by other methods. A reduction in the estimated impact from existing parks does not suggest, however, that protection is unable to lower clearing. Rather, it indicates the importance of variation across locations in how much impact protection could possibly have on rates of deforestation.Matching, then, bundles improved estimates of the average impact of protection with guidance on where new parks’ impacts will be highest.While many factors will determine where new protected areas will be sited in the future, we claim that the variation across space in protection’s impact on deforestation rates should inform site choice.


Park Location Affects Forest Protection: Land Characteristics Cause Differences in Park Impacts across Costa Rica

Alexander Pfaff, Juan Robalino, G. Arturo Sanchez-Azofeifa, Kwaw S. Andam, Paul J. Ferraro
The B.E. Journal of Economic Analysis & Policy: Vol. 9: Iss. 2 (Contributions), Article 5.

PDF link iconTo support conservation planning, we ask whether a park’s impact on deforestation rates varies with observable land characteristics that planners could use to prioritize sites. Using matching methods to address bias from non-random location, we find deforestation impacts vary greatly due to park lands’ characteristics. Avoided deforestation is greater if parks are closer to the  capital city, in sites closer to national roads, and on lower slopes. In allocating scarce conservation resources, policy makers may consider many factors such as the ecosystem services provided by a site and the costs of acquiring the site. Pfaff and Sanchez 2004 claim impact can rise with a focus upon threatened land, all else equal. We provide empirical support in the context of Costa Rica’s renowned park system. This insight, alongside information on eco-services and land costs, should guide investments.


High and Far: Biases in the Location of Protected Areas

Lucas N. Joppa, Alexander Pfaff
PLoS ONE 2009 4(12): e8273. doi:10.1371/journal.pone.0008273

PDF link iconBackground: About an eighth of the earth’s land surface is in protected areas (hereafter ‘‘PAs’’), most created during the 20th century. Natural landscapes are critical for species persistence and PAs can play a major role in conservation and in climate policy. Such contributions may be harder than expected to implement if new PAs are constrained to the same kinds of locations that PAs currently occupy.

Methodology/Principal Findings: Quantitatively extending the perception that PAs occupy ‘‘rock and ice’’, we show that across 147 nations PA networks are biased towards places that are unlikely to face land conversion pressures even in the absence of protection. We test each country’s PA network for bias in elevation, slope, distances to roads and cities, and suitability for agriculture. Further, within each country’s set of PAs, we also ask if the level of protection is biased in these ways. We find that the significant majority of national PA networks are biased to higher elevations, steeper slopes and greater distances to roads and cities. Also, within a country, PAs with higher protection status are more biased than are the PAs with lower protection statuses.

Conclusions/Significance: In sum, PAs are biased towards where they can least prevent land conversion (even if they offer perfect protection). These globally comprehensive results extend findings from nation-level analyses. They imply that siting rules such as the Convention on Biological Diversity’s 2010 Target [to protect 10% of all ecoregions] might raise PA impacts if applied at the country level. In light of the potential for global carbon-based payments for avoided deforestation or REDD, these results suggest that attention to threat could improve outcomes from the creation and management of PAs.


Human choices and policies’ impacts on ecosystem services: improving evaluations of payment and park effects on conservation and carbon

Alexander Pfaff, Juan Robalino
Engel, S. and C. Palmer, editors, “Avoided Deforestation: Prospects for Mitigating Climate Change”, Routledge Explorations in Environmental Economics 2009

PDF link iconThis chapter conveys why human choices complicate correct evaluations of impacts. Unobservable land choices, choices affecting policy location and interactions among choices complicate both ex post impact evaluation and ex ante policy planning. Based on application of proper methods to Costa Rica, we then suggest how these hurdles can best be addressed. We provide examples of: how a best practice deforestation baseline rightly conveys the constraints on the impact the pioneering Costa Rican eco-payments programme could have; why it may be critical to have different baselines for different locations to correctly infer the impacts of Costa Rican protected areas; and how choices by conservation agencies and landowners can determine the bias within heretofore typical approaches to impact evaluation.


Behavior, Environment, and Health in Developing Countries: evaluation and valuation

Subhrendu Pattanayak, Alexander Pfaff
Annual Review of Resource Economics (2009) 1:183–217

PDF link iconWe consider health and environmental quality in developing countries, where limited resources constrain behaviors that combat enormously burdensome health challenges. We focus on four huge challenges that are preventable (i.e., are resolved in rich countries). We distinguish them as special cases in a general model of household behavior, which is critical and depends on risk information. Simply informing households may achieve a lot in the simplest challenge (groundwater arsenic); yet, for the three infectious situations discussed (respiratory, diarrhea, and malaria), community coordination and public provision may also be necessary. More generally, social interactions may justify additional policies. For each situation, we discuss the valuation of private spillovers (i.e., externalities) and evaluation of public policies to reduce environmental risks and spillovers. Finally, we reflect on open questions in our model and knowledge gaps in the empirical literature including the challenges of scaling up and climate change.


Measuring the effectiveness of protected-area networks in reducing deforestation

Kwaw Andam, Paul Ferraro, Alexander Pfaff, Juan Robalino, G. Arturo Sanchez-Azofeifa
PNAS 105(42):16089-16094

PDF link iconGlobal efforts to reduce tropical deforestation rely heavily on the establishment of protected areas. Measuring the effectiveness of these areas is difficult because the amount of deforestation that would have occurred in the absence of legal protection cannot be directly observed. Conventional methods of evaluating the effectiveness of protected areas can be biased because protection is not randomly assigned and because protection can induce deforestation spillovers (displacement) to neighboring forests. We demonstrate that estimates of effectiveness can be substantially improved by controlling for biases along dimensions that are observable, measuring spatial spillovers, and testing the sensitivity of estimates to potential hidden biases. We apply matching methods to evaluate the impact on deforestation of Costa Rica’s renowned protected-area system between 1960 and 1997. We find that protection reduced deforestation: approximately 10% of the protected forests would have been deforested had they not been protected. Conventional approaches to evaluating conservation impact, which fail to control for observable covariates correlated with both protection and deforestation, substantially overestimate avoided deforestation (by over 65%, based on our estimates). We also find that deforestation spillovers from protected to unprotected forests are negligible. Our conclusions are robust to potential hidden bias, as well as to changes in modeling assumptions. Our results show that, with appropriate empirical methods, conservation scientists and policy makers can better understand the relationships between human and natural systems and can use this to guide their attempts to protect critical ecosystem services.


Effects of Poverty on Deforestation: distinguishing behavior from location

Alexander Pfaff, Suzi Kerr, Romina Cavatassi, Benjamin Davis, Leslie Lipper, G. Arturo Sanchez-Azofeifa, J. Timmins
Economics of poverty, environment and natural resource use (chapter 6).

PDF link iconWe review many theoretical predictions that link poverty to deforestation and then examine poverty’s net impact empirically using multiple observations of all of Costa Rica after 1960. Countrywide disaggregate (district-level) data facilitate analysis of both poverty’s location and its impact on forest. If the characteristics of the places the poor live are not controlled for, then poverty’s impact is confounded with differences between poorer and less poor areas and we find no significant effect of poverty. Using our data over space and time to control for effects of locations’ differing characteristics, we find that the poorer are on land whose relative quality discourages forest clearing, such that with these controls the poorer areas are cleared more. The latter result suggests that poverty reduction aids the forest. For the poorest areas, this result is weaker but another effect is found: deforestation responds less to productivity, i.e., the poorest have less ability to expand or to reduce given land quality.


Road Impacts in Brazilian Amazonia

Alexander Pfaff, Alisson Barbieri, Thomas Ludewigs, Frank Merry, Stephen Perz, Eustaquio Reis
Chapter in “Amazonia and Global Change” book (American Geophysical Union, linked to the NASA LBA project)

PDF link iconWe examine the evidence on Amazonian road impacts with a strong emphasis on context. Impacts of a new road, on either deforestation or socioeconomic outcomes, depend upon the conditions into which roads are placed. Conditions that matter include the biophysical setting, such as slope, rainfall, and soil quality, plus externally determined socioeconomic factors like national policies, exchange rates, and the global prices of beef and soybeans. Influential conditions also include all prior infrastructural investments and clearing rates. Where development has already arrived, with significant economic activity and clearing, roads may decrease forest less and raise output more than where development is arriving, while in pristine areas, short-run clearing may be lower than immense long-run impacts. Such differences suggest careful consideration of where to invest further in transport.


Can information alone change behavior? Response to arsenic contamination of groundwater in Bangladesh

Malgosia Madajewicz, Alexander Pfaff, Alexander van Geen, Joseph Graziano, Iftikhar Hussein, Hasina Momotaj, Roksana Sylvia, Habibul Ahsan
Journal of Development Economics 84 (2007) 731–754

PDF link iconWe study how effectively information induces Bangladeshi households to avoid a health risk. The response to information is large and rapid; knowing that the household’s well water has an unsafe concentration of arsenic raises the probability that the household changes to another well within one year by 0.37. Households who change wells increase the time spent obtaining water fifteen-fold. We identify a causal effect of information, since incidence of arsenic is uncorrelated with household characteristics. Our door-to-door information campaign provides well-specific arsenic levels without which behavior does not change. Media communicate general information about arsenic less expensively and no less effectively.


Road Investments, Spatial Spillovers and Deforestation in the Brazilian Amazon

Alexander Pfaff, Juan Robalino, Robert Walker, Steven Aldrich, Marcellus Caldas, Eustaquio Reis, Stephen Perz, Claudio Bohrer, Eugenio Arima, William Laurance, Kathryn Kirby
Journal of Regional Science 2007 volume 47, no. 1, 2007, pp. 109–123

PDF link iconUnderstanding the impact of road investments on deforestation is part of a complete evaluation of the expansion of infrastructure for development.We find evidence of spatial spillovers from roads in the Brazilian Amazon: deforestation rises in the census tracts that lack roads but are in the same county as and within 100 km of a tract with a new paved or unpaved road. At greater distances from the new roads the evidence is mixed, including negative coefficients of inconsistent significance between 100 and 300 km, and if anything, higher neighbor deforestation at distances over 300 km.


Costa Rica’s Payment for Environmental Services Program: Intention, Implementation, and Impact

G. Arturo Sanchez-Azofeifa, Alexander Pfaff, Juan Robalino, Judson Boomhower
Conservation Biology 2007 volume 21, number 5, 1165–1173

PDF link iconWe evaluated the intention, implementation, and impact of Costa Rica’s program of payments for environmental services (PSA), which was established in the late 1990s. Payments are given to private landowners who own land in forest areas in recognition of the ecosystem services their land provides. To characterize the distribution of PSA in Costa Rica, we combined remote sensing with geographic information system databases and then used econometrics to explore the impacts of payments on deforestation. Payments were distributed broadly across ecological and socioeconomic gradients, but the 1997–2000 deforestation rate was not significantly lower in areas that received payments. Other successful Costa Rican conservation policies, including those prior to the PSA program, may explain the current reduction in deforestation rates. The PSA program is a major advance in the global institutionalization of ecosystem investments because few, if any, other countries have such a conservation history and because much can be learned from Costa Rica’s experiences.


Responses of 6500 households to arsenic mitigation in Araihazar, Bangladesh

Alisa Opar, Alexander Pfaff, A.A. Seddique, Kazi Matin Ahmed, Joseph H. Graziano, Alexander van Geen
Health & Place 13 (2007) 164–172

PDF link iconThis study documents the response of 6500 rural households in a 25 km2 area of Bangladesh to interventions intended to reduce their exposure to arsenic contained in well water. The interventions included public education, posting test results for arsenic on the wells, and installing 50 community wells. Sixty-five percent of respondents from the subset of 3410 unsafe wells changed their source of drinking water, often to new and untested wells. Only 15% of respondents from the subset of safe wells changed their source, indicating that health concerns motivated the changes. The geo-referenced data indicate that distance to the nearest safe well also influenced household responses.


Climate, Stream Flow Prediction and Water Management in Northeast Brazil: societal trends and forecast value

Kenneth Broad, Alexander Pfaff, Renzo Taddei, Sankar Arumugam, Upmanu Lall, Francisco Assis de Souza Filho
Climatic Change (2007) 84:217–239

PDF link iconWe assess the potential benefits from innovative forecasts of the stream flows that replenish reservoirs in the semi-arid state of Ceará, Brazil. Such forecasts have many potential applications. In Ceará, they matter for both water-allocation and participatory-governance issues that echo global debates. Our qualitative analysis, based upon extensive fieldwork with farmers, agencies, politicians and other key actors in the water sector, stresses that forecast value changes as a society shifts. In the case of Ceará, current constraints on the use of these forecasts are likely to be reduced by shifts in water demand, water allocation in the agricultural Jaguaribe Valley, participatory processes for water allocation between this valley and the capital city of Fortaleza, and risk perception. Such changes in the water sector can also have major distributional impacts.


Will buying tropical forest carbon benefit the poor? evidence from Costa Rica

Alexander Pfaff, Suzi Kerr, Leslie Lipper, Romina Cavatassi, Benjamin Davis, Joanna Hendy, G. Arturo Sanchez-Azofeifa
Land Use Policy 24 (2007) 600–610

PDF link iconWe review claims linking both payments for carbon and poverty to deforestation. We examine these effects empirically for Costa Rica during the late 20th century using an econometric approach that addresses the irreversibilities in deforestation. We find significant effects of the relative returns to forest on deforestation rates. Thus, carbon payments would induce  conservation and also carbon sequestration, and if land users were poor could conserve forest while addressing rural poverty. We note that the poor appear to be marginalized in the sense of living where land profitability is lower. Those areas also have more forest. We find that poorer areas may have a higher supply response to payments, but even without this effect poor areas might be included and benefit more due to higher (per capita) forest area. They might be included less due to transactions costs, though. Unless the Clean Development Mechanism of the Kyoto Protocol is modified in its implementation to allow credits from avoided  deforestation, such benefits are likely to be limited.


Payments for Ecosystem Services: why precision and targeting matter

Francisco Alpizar, Allen Blackman, Alexander Pfaff
Resources 2007 volume 165:20-22

PDF link iconEven a perfect measure of the ecosystem services provided by each parcel enrolled in a PES program would be insufficient to measure the overall effectiveness of the program. The simple reason is that if a PES program does not lead to an increase in the provision of ecosystem services compared to what would have happened in the absence of the program—that is, the baseline or “counterfactual”—then it has not accomplished anything. Imagine a PES program focused on forest conservation that makes payments to managers of ecologically rich forest land, who have no incentive to clear the land because it is illsuited for logging, agriculture, or urbanization. Payments to these managers would have little impact on deforestation because the risk of clearing was minimal to begin with. In contrast, payments to managers who have incentives to clear their land would be much more likely to have an impact.


Estimating Spatial Interactions in Deforestation Decisions

Juan Robalino, Alexander Pfaff, G. Arturo Sanchez-Azofeifa
Frontiers of Biodiversity Economics, Cambridge University Press

PDF link iconThis chapter is structured as follows. Section 2 describes a simple model of interactions in the context of deforestation, based on an equilibrium in beliefs about the neighbours’ actions. Section 3 discusses empirical issues in measurement of interactions and the benefits of using an instrumental variable approach. Data requirements for analysing neighbours’ interactions in deforestation decisions are discussed in section 4. Finally, results for two regions within Costa Rica, as well as discussion of how to obtain the equilibria once the parameters of the model are estimated, are presented in section 5.


Reduction in Urinary Arsenic Levels in Response to Arsenic Mitigation Efforts in Araihazar, Bangladesh

Yu Chen, Alexander van Geen, Joseph H. Graziano, Alexander Pfaff, Malgosia Madajewicz, Faruque Parvez, A.Z.M Iftehkar Hussain, Vesna Slavkovich, Tariqul Islam, Habibul Ahsan
Environmental Health Perspectives, Vol. 115, No. 6 (Jun., 2007), pp. 917-923

PDF link iconBACKGROUND: There is a need to identify and evaluate an effective mitigation program for arsenic exposure from drinking water in Bangladesh.   OBJECTIVE: We evaluated the effectiveness of a multifaceted mitigation program to reduce As exposure among 11,746 individuals in a prospective cohort study initiated in 2000 in Araihazar, Bangladesh, by interviewing participants and measuring changes in urinary As levels. METHODS: The interventions included  a) person-to-person reporting of well test results and health education; b) well labeling and village-level health education; and c) installations of fifty deep, low-As community wells in villages with the highest As exposure. RESULTS: Two years after these interventions, 58% of the 6,512 participants with unsafe wells (As >=50 micrograms/L) at baseline had responded by switching to other wells. Well labeling and village-level health education was positively related to switching to safe wells (As < 50 micrograms/L) among participants with unsafe wells [rate ratio(RR)= 1.84; 95% confidence interval(CI), 1.60-2.11] and inversely related to any well switching among those with safe wells (RR = 0.80; 95% CI, 0.66-0.98). The urinary As level in participants who switched to a well identified as safe (< 50 micrograms As/L) dropped from an average of 375 micrograms As/g creatinine to 200 micrograms As/g creatinine, a 46% reduction toward the average urinary As content of 136 micrograms As/g creatinine for participants that used safe wells throughout. Urinary As reduction was positively related to educational attainment, body mass index, never-smoking, absence of skin lesions, and time since switching (p for trend< 0.05). CONCLUSIONS: Our   study shows that testing of wells and informing households of the consequences of As exposure, combined with installation of deep community wells where most needed, can effectively address the continuing public health emergency from arsenic in drinking water in Bangladesh.

Ensuring Safe Drinking Water in Bangladesh

M.F. Ahmed, S. Ahuha, M. Alauddin, S.J. Hug, J.R. Lloyd, A. Pfaff, T. Pichler, C. Saltikov, M. Stute, A. van Geen
Science volume 314 (December 15, 2006): 1687-1688

PDF link iconExcessive levels of arsenic in drinking water is a vast health problem in Southeast Asia. Several viable approaches to mitigation could drastically reduce arsenic exposure, but they all require periodic testing.


UNICEF K.A.P. Survey Data Report

Malgosia Madajewicz, Alexander Pfaff
UNICEF Report (with Jan Willem Rosenboom, unofficial earlier draft attached here)

PDF link iconUNICEF Bangladesh, with assistance from a number of non-governmental agencies (NGOs), conducted surveys to assess the impact of arsenic contamination in Bangladesh. The surveys aimed to measure the knowledge levels, attitudes and behavioral patterns of respondents living in arsenic-affected areas. The first survey, referred to hereafter as the baseline survey, or baseline, was conducted between July and September of 2001. The subsequent survey, referred to as the follow-up survey, or follow-up, took place in March-May, 2002. In the period between surveys, UNICEF and other governmental and non-governmental agencies carried out dissemination programs to make people aware of the problems associated with arsenic contamination. The primary objective of this report is to ascertain whether these dissemination programs increased the level of arsenic-related awareness and knowledge. We would also like to find out whether varying levels of knowledge and attitude among the respondents appear to explain the variance in their stated willingness to take action or to spend money to prevent arsenic-related problems.

Household Production and Environmental Kuznets Curves

Alexander Pfaff, Shubham Chaudhuri, Howard L.M. Nye
Environmental and Resource Economics 27: 187–200, 2004.

PDF link iconThis paper provides a theoretical explanation for the widely debated empirical finding of “Environmental Kuznets Curves”, i.e., U-shaped relationships between per-capita income and indicators of environmental quality. We present a household-production model in which the degradation of environmental quality is a by-product of household activities. Households can not directly purchase environmental quality, but can reduce degradation by substituting more expensive cleaner inputs to production for less costly dirty inputs. If environmental quality is a normal good, one expects substitution towards the less polluting inputs, so that increases in income will increase the quality of the environment. It is shown that this only holds for middle income households. Poorer households spend all income on dirty inputs. When they buy more, as income rises, the pollution also rises. they do not want to substitute, as this would reduce consumption of non-environmental services for environmental amenities that are already abundant. Thus, as income rises from low to middle levels, a U shape can result. Yet an N shape might eventually result, as richer households spend all income on clean inputs. Further substitution possibilities are exhausted. Thus as income rises again pollution rises and environmental quality falls.


Endowments, preferences, technologies and abatement: growth-environment microfoundations

Alexander Pfaff, Shubham Chaudhuri, Howard L.M. Nye
Int. J. Global Environmental Issues (2004) volume 4 number 4: 209-228

PDF link iconWill economic growth inevitably degrade the environment, throughout development? We present a household-level framework emphasising the trade-off between consumption that causes pollution and pollution-reducing abatement. Our model provides a simple explanation for upward-turning, non-monotonic paths of environmental quality during economic growth. Its innovation yields sufficient conditions that simultaneously address preferences and technologies. With standard preferences, an asymmetric endowment (i.e., at zero income, consumption is also zero but environmental quality is positive) leads low-income households not to abate, and further this condition is sufficient for an environmental Kuznets curve (EKC) for a wide range of abatement technologies. Without such an endowment, however, even strong economies of scale in abatement are, on their own, insufficient for an EKC


Aid, economic growth and environmental sustainability: rich-poor interactions and environmental choices in developing countries

Alexander Pfaff, Paulo Barelli, Shubham Chaudhuri
Int. J. Global Environmental Issues (2004) volume 4 numbers 1/2/3: 139-159

PDF link iconRich-poor interactions complicate the search for a stable Environmental Kuznets Curve (an ‘inverted U’ relationship between income per-capita and environmental degradation). We show that aid from richer to poorer countries to support investments in environment, in either of two forms, alters the income-environment relationships that otherwise exist, lowering levels of degradation in the poorer countries conditional upon their incomes. Yet even with environmental aid, in our model environmental quality eventually falls as economic growth continues, although ongoing innovation could change that conclusion. In light of this result, we show that subsidies to clean goods, one form of technological-transfer aid programme, dominate income transfers as environmental aid policy by the rich. Given that aid matters, we then show that when rich countries degrade the environment, a perverse effect exists: when an aid-giving country becomes richer, it gives less aid to the poor country. This is stronger when that degradation is durable, that is, when consumption and degradation by the rich country in the past has durable effects upon the environment.


To Err on Humans is not Benign: incentives for adoption of medical error-reporting systems

Joshua Graff Zivin, Alexander Pfaff
Journal of Health Economics 23 (2004) 935–949

PDF link iconConcerns about frequent and harmful medical errors have led policy makers to advocate the creation of a system for medical error reporting. Health providers, fearing that reported information about errors would be used against them under the current medical malpractice system, have been reluctant to participate in such reporting systems.We propose a re-design of the malpractice system – one in which penalties are a function of the health provider’s reporting efforts – to overcome this incentive problem.We also consider some alternatives to this mechanism that address two important ways in which reporting effort may not be observable: hospitals may have interests distinct from individual physicians and may not be able to observe their reporting efforts, and a regulatory agency or a court may not be able to adequately observe reporting efforts by a provider.