At first the tobit models according to T. Amemiya’s classification ([1]) are presented in the paper. Next, expected values and marginal effects in these models are obtained. In the tobit models marginal effects are not equal to coefficients of the model in general. To get a proper interpretation in the considered models, it is necessary to obtain marginal effects as a partial deviation of the expected values. Moreover, marginal effects are different for binary and continuous variables.
[1] Amemiya T. (1984), Tobit Models: A survey, Journal of Econometrics, vol. 24, s. 3-61.
[2] Flood L., Gr°asj¨o U. (1998), Regression Analysis and Time Use Data: A Comparison of Microeconometric Approaches with Data from the Swedish Time Use Survey (HUS), Working Papers in Economics, nr 5, School of Economics and Commercial Law, G¨oteborg University.
[3] Greene W. (1999), Marginal Effects in the Censored Regression Model, Econometrics Letters, nr 1(64).
[4] Greene W. (2003), Econometric Analysis, 5th ed., Prentice-Hall, Inc, New Jersey.
[5] Gruszczyński M. (2002), Modele i prognozy zmiennych jakościowych w finansach i bankowości, wyd. 2, Monografie i Opracowania 490, Oficyna Wydawnicza SGH, Warszawa.
[6] Heckman J. (1974), Shadow Prices, Market Wages, and Labor Supply, Economertica, vol. 42, nr 4, s. 679–694.
[7] Heckman J. (1976), The Common Structure of Statistical Models of Truncation, Sample Selection and Limited Dependent Variables and a Simple Estimator for Such Models, Annals of Economic and Social Measurement, nr 5/4, 1976, s. 475–492.
[8] Heckman J. (1979), Sample Selection Bias as a Specification Error, Econometrica, vol. 47, nr 1, s. 153-161.
[9] Heckman J. (1987), Selection Bias and Self-Selection [w:] The New Palgrave: A Dictionary of Economics, vol. 1-4, pod red. J. Eatwell, M. Milgate, P. Newman, Macmillan Press, London, s. 287-297.
[10] Heckman J. (1990), Varieties of Selection Bias, American Economic Review, 80, s. 313-318.
[11] Heckman J. (2003), Microdata, Heterogeneity and the Evaluation of Public Policy [w:] Nobel Lectures in Economic Sciences 1996 – 2000, T. Persson (ed.), World Scientific Publishing Co., Singapore, s. 255-322.
[12] Jones A.M. (1989), A Double-Hurdle Model of Cigarette Consumption, Journal of Applied Econometrics, vol. 4, s. 23-39.
[13] Jones A.M. (1992), A Note on Computation of the Double-Hurdle Model with Dependence with an Application to Tobaco Expenditure, Bulletin of Economic Research, vol. 44, nr 1, s. 67-74.
[14] Kostrzewska J. (2003), Model tobitowy jako szczególny przypadek cenzurowanego modelu regresji [w:] Przestrzenno–czasowe modelowanie i prognozowanie zjawisk gospodarczych, pod red. A. Zeliasia, Wyd. AE w Krakowie, Kraków, s. 397-404.
[15] Kostrzewska J. (2004), Model regresji dla danych dobieranych do próby według nielosowego kryterium, Zeszyty Naukowe AE w Krakowie, nr 666, Prace z zakresu prognozowania, Kraków, s. 111-117.
[16] Kostrzewska J. (2008), Zastosowanie wybranych modeli tobitowych do opisu tygodniowej liczby godzin pracy [w:] Taksonomia 15. Klasyfikacja i analiza danych – teoria i zastosowania, pod red. K. Jajugi i M. Walesiaka, Prace Naukowe Uniwersytetu Ekonomicznego we Wrocławiu, Wrocław.
[17] Kostrzewska J. (2009), Truncated and Censored Dependent Variables and Their Models [w:] Statistical Analysis of the Economic and Social Consequences of Transition Processes in Central-East European Countries, ed. by J. Pociecha, Studia i Prace UEK, nr 6, UEK, Kraków.
[18] Kostrzewska J. (2011), Analiza porównawcza tygodniowego czasu pracy zamężnych kobiet pracujących na własny rachunek lub najemnie, [w:] Osiągnięcia i perspektywy modelowania i prognozowania zjawisk społeczno-gospodarczych, pod red. B. Pawełek, Wyd. UEK, Kraków.
[19] Kostrzewska J. (2011), Modele regresji zmiennych cenzurowanych w analizie rynku pracy w Polsce, manuskrypt, UEK, Kraków.
[20] Maddala G.S. (1987), Censored Data Models [w:] The New Palgrave: A Dictionary of Economics, ed. by J. Eatwell, M. Milgate, P. Newman, Macmillan Press, London, vol. 1, s. 384-385.
[21] Maddala G.S. (1994), Limited-Dependent and Qualitative Variables in Econometrics, Cambridge University Press, Cambridge (pierwsze wyd. w 1983 roku).
[22] McDonald J.F., Moffitt R.A. (1980), The Uses of Tobit Analysis, Review of Economics and Statistics, vol. LXII, s. 318-321.
[23] Roneck D.W. (1992), Learning More from Tobit Coefficients: Extending a Comparative Analysis of Political Protests, American Sociological Review, vol. 57, nr 4, s. 503-507.
[24] Tobin J. (1958), Estimation of Relationships for Limited Dependent Variables, Econometrica, vol. 26, s. 24-36.