A. Abadie, Semiparametric Difference-in-Differences Estimators, Review of Economic Studies, vol.72, issue.1, pp.1-19, 2005.
DOI : 10.1111/0034-6527.00321

A. Abadie, J. Angrist, and G. Imbens, Instrumental Variables Estimates of the Effect of Subsidized Training on the Quantiles of Trainee Earnings, Econometrica, vol.70, issue.1, pp.91-117, 2002.
DOI : 10.1111/1468-0262.00270

A. Abadie, D. Drukker, J. L. Herr, and G. W. Imbens, Implementing Matching Estimators for Average Treatment Effects in Stata, Stata Journal, vol.4, issue.3, pp.290-311, 2004.

A. Abadie and G. W. Imbens, Large Sample Properties of Matching Estimators for Average Treatment Effects, On the Failure of the Bootstrap for Matching Estimators, pp.235-267, 2002.
DOI : 10.1111/j.1468-0262.2006.00655.x

J. D. Angrist and A. B. Krueger, Empirical Strategies in Labor Economics, Handbook of Labor Economics IIIA of Handbook in Economics, pp.1277-1366, 1999.
DOI : 10.1016/S1573-4463(99)03004-7

S. Chabé-ferret and J. Subervie, Evaluation de l'Effet Propre des Mesures Agro-Environnementales du PDRN Rapport d'évaluation, Cemagref, 2000.

G. Ducos and P. Dupraz, Private Provision of Environmental Services and Transaction Costs, Discussion paper, 2006.

E. Duflo, Schooling and Labor Market Consequences of School Construction in Indonesia: Evidence from an Unusual Policy Experiment, American Economic Review, vol.91, issue.4, pp.795-813, 2001.
DOI : 10.3386/w7860

M. Fall and T. Magnac, How Valuable Is On-Farm Work to Farmers?, American Journal of Agricultural Economics, vol.86, issue.1, pp.267-281, 2004.
DOI : 10.1111/j.0092-5853.2004.00577.x

J. Fan, Design-adaptive Nonparametric Regression, Journal of the American Statistical Association, vol.26, issue.420, pp.998-1004, 1992.
DOI : 10.1214/aos/1176343886

S. Firpo, Efficient Semiparametric Estimation of Quantile Treatment Effects, Econometrica, vol.75, issue.1, pp.259-276, 2007.
DOI : 10.1111/j.1468-0262.2007.00738.x

M. Greenstone and T. Gayer, Quasi-experimental and experimental approaches to environmental economics, Journal of Environmental Economics and Management, vol.57, issue.1, pp.21-44, 2009.
DOI : 10.1016/j.jeem.2008.02.004

G. Hazeu, B. Elbersen, C. Van-diepen, B. Baruth, and M. Metzger, Regional typologies of ecological and biophysical context, Discussion paper, System for Environmental and Agricultural Modelling Linking European Science and Society (SEAMLESS), 2006.

J. J. Heckman and V. J. Hotz, Choosing among Alternative Nonexperimental Methods for Estimating the Impact of Social Programs: The Case of Manpower Training, Journal of the American Statistical Association, vol.70, issue.408, pp.862-874, 1989.
DOI : 10.1080/01621459.1989.10478848

J. J. Heckman, H. Ichimura, and P. E. Todd, Matching As An Econometric Evaluation Estimator: Evidence from Evaluating a Job Training Programme, The Review of Economic Studies, vol.64, issue.4, pp.605-654, 1997.
DOI : 10.2307/2971733

J. J. Heckman, R. J. Lalonde, and J. A. Smith, The Economics and Econometrics of Active Labor Market Programs, Handbook of Labor Economics, pp.31-1865, 1999.
DOI : 10.1016/S1573-4463(99)03012-6

J. J. Heckman and R. Robb, Alternative Methods for Evaluating the Impact of Interventions, " in Longitudinal Analysis of Labor Market Data, pp.156-245, 1985.

J. J. Heckman and J. Smith, Evaluating the Welfare State, Econometrics and Economics in the 20th Century, 1998.

J. J. Heckman, S. Urzua, and E. Vytlacil, Understanding Instrumental Variables in Models with Essential Heterogeneity, Review of Economics and Statistics, vol.62, issue.3, pp.389-432, 2006.
DOI : 10.2307/1392256

J. J. Heckman and E. J. Vytlacil, Local instrumental variables and latent variable models for identifying and bounding treatment effects, Proceedings of the National Academy of Sciences, pp.96-4730, 1999.
DOI : 10.1073/pnas.96.8.4730

P. W. Holland, Statistics and Causal Inference, Journal of the American Statistical Association, vol.10, issue.396, pp.945-970, 1986.
DOI : 10.1080/01621459.1980.10477517

G. W. Imbens, Nonparametric Estimation of Average Treatment Effects Under Exogeneity: A Review, Review of Economics and Statistics, vol.45, issue.4, pp.4-29, 2004.
DOI : 10.1111/1468-2354.t01-1-00055

G. W. Imbens and J. D. Angrist, Identification and Estimation of Local Average Treatment Effects, Econometrica, vol.62, issue.2, pp.467-476, 1994.
DOI : 10.2307/2951620

R. J. Jones, R. Hiederer, E. Rusco, and L. Montanarella, Estimating organic carbon in the soils of Europe for policy support, European Journal of Soil Science, vol.16, issue.5, pp.56-655, 2005.
DOI : 10.1191/026765800669966932

M. Lechner, Program Heterogeneity and Propensity Score Matching: An Application to the Evaluation of Active Labor Market Policies, Review of Economics and Statistics, vol.3, issue.2, pp.205-220, 2002.
DOI : 10.2307/1164933

R. E. Lopez, Estimating labor supply and production decisions of self-employed farm producers, European Economic Review, vol.24, issue.1, pp.61-82, 1984.
DOI : 10.1016/0014-2921(84)90013-8

L. Lynch, W. Gray, and J. Geoghegan, Are Farmland Preservation Program Easement Restrictions Capitalized into Farmland Prices? What Can a Propensity Score Matching Analysis Tell Us?, Review of Agricultural Economics, vol.29, issue.3, pp.29-502, 2007.
DOI : 10.1111/j.1467-9353.2007.00361.x

L. Lynch and X. Liu, Impact of Designated Preservation Areas on Rate of Preservation and Rate of Conversion: Preliminary Evidence, American Journal of Agricultural Economics, vol.89, issue.5, pp.1205-1210, 2007.
DOI : 10.1111/j.1467-8276.2007.01085.x

M. J. Metzger, R. G. Bunce, R. H. Jongman, C. A. Mücher, and J. W. Watkins, A climatic stratification of the environment of Europe, Global Ecology and Biogeography, vol.1, issue.6, pp.14-549, 2005.
DOI : 10.1111/j.1466-822X.2005.00190.x

A. Pufahl and C. R. Weiss, Evaluating the effects of farm programmes: results from propensity score matching, European Review of Agricultural Economics, vol.36, issue.1, pp.79-101, 2009.
DOI : 10.1093/erae/jbp001

P. R. Rosenbaum and D. B. Rubin, The central role of the propensity score in observational studies for causal effects, Biometrika, vol.70, issue.1, pp.41-55, 1983.
DOI : 10.1093/biomet/70.1.41

D. B. Rubin, Bayesian Inference for Causal Effects: The Role of Randomization, The Annals of Statistics, vol.6, issue.1, pp.34-58, 1978.
DOI : 10.1214/aos/1176344064

J. S. Sekhon, Forthcoming): " Multivariate and Propensity Score Matching Software with Automated Balance Optimization: The Matching package for R, Journal of Statistical Software

A. M. Shaikh, M. Simonsen, E. J. Vytlacil, and N. Yildiz, A specification test for the propensity score using its distribution conditional on participation, Journal of Econometrics, vol.151, issue.1, pp.33-46, 2009.
DOI : 10.1016/j.jeconom.2009.01.014

J. A. Smith and P. E. Todd, Does Matching Overcome Lalonde's Critique of Nonexperimental Estimators?, SSRN Electronic Journal, vol.125, issue.12, pp.305-353, 2005.
DOI : 10.2139/ssrn.286297

J. Strauss, The Theory and Comparative Statics of Agricultural Household Models: A General Approach, Agricultural household models, extensions applications and policies, pp.71-91, 1986.

P. E. Todd, Chapter 60 Evaluating Social Programs with Endogenous Program Placement and Selection of the Treated, Handbook of Development Economics, pp.60-3847, 2007.
DOI : 10.1016/S1573-4471(07)04060-0