We investigate conditions sufficient for identification of average treatment effects using instrumental variables. First we show that the existence of valid instruments is not sufficient to identify any meaningful average treatment effect. We then establish that the combination of an instrument and a condition on the relation between the instrument and the participation status is sufficient for identification of a local average treatment effect for those who can be induced to change their participation status by changing the value of the instrument. Finally we derive the probability limit of the standard IV estimator under these conditions. It is seen to be a weighted average of local average treatment effects.

Evolution and Rationality Some Recent Game-Theoretic Results. Identification and Estimation of Local Average Treatment Effects

Since the early 1980s, the econometric analysis of duration variables has become widespread. This chapter provides an overview of duration analysis, with an emphasis on the specification and identification of duration models, and with special attention to models for multiple durations. Most of the chapter deals with so-called reduced-form duration models, notably the popular Mixed Proportional Hazard (MPH) model and its multivariate extensions. The MPH model is often used to describe the relation between the empirical exit rate and “background variables” in a concise way. However, since the applications usually interpret the results in terms of some economic-theoretical model, we examine to what extent the deep structural parameters of some important theoretical models can be related to reduced-form parameters. We subsequently examine the specification and identification of the MPH model in great detail, we provide intuition on what drives identification, and we infer to what extent biases may occur because of misspecifications. This examination is carried out separately for the case of single-spell data and the case of multi-spell data. We also compare different functional forms for the unobserved heterogeneity distribution. Next, we examine models for multiple durations. In the applied econometric literature on the estimation of multiple-duration models, the range of different models is actually not very large. Typically, the models allow for dependence between the duration variables by way of their unobserved determinants, with each single duration following its own MPH model. In addition to this, the model may allow for an interesting “causal” effect of one duration on the other, as motivated by an underlying economic theory. For all these models we examine the conditions for identification. Some of these are intimately linked to particular estimation strategies. The multiple-duration model where the marginal duration distributions each satisfy an MPH specification, and the durations can only be dependent by way of their unobserved determinants, is called the Multivariate Mixed Proportional Hazard (MMPH) model. For this model, we address the issue of the dimensionality of the heterogeneity distribution and we compare the flexibility of different parametric heterogeneity distributions. On a number of occasions, we incorporate recent insights from the biostatistical literature on duration analysis, and we contrast points of view in this literature to those in the econometric literature. Finally, throughout the chapter, we discuss the importance of the possible collection of additional data.

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Duration Models: Specification, Identification, and Multiple Durations

It is increasingly common for analysts to seek out the opinions of individuals and organizations using attitudinal scales such as degree of satisfaction or importance attached to an issue Examples include levels of obesity, seriousness of a health condition, attitudes towards service levels, opinions on products, voting intentions, and the degree of clarity of contracts Ordered choice models provide a relevant methodology for capturing the sources of influence that explain the choice made amongst a set of ordered alternatives The methods have evolved to a level of sophistication that can allow for heterogeneity in the threshold parameters, in the explanatory variables (through random parameters), and in the decomposition of the residual variance This book brings together contributions in ordered choice modeling from a number of disciplines, synthesizing developments over the last fifty years, and suggests useful extensions to account for the wide range of sources of influence on choice

Modeling Ordered Choices: A Primer

This paper summarizes the contributions of microeconometrics to economic knowledge Four main themes are developed (1) Microeconometricians developed new tools to respond to econometric problems raised by the analysis of the new sources of micro data produced after the Second World War (2) Microeconometrics improved on aggregate time‐series methods by building models that linked economic models for individuals to data on individual behavior (3) An important empirical regularity detected by the field is the diversity and heterogeneity of behavior This heterogeneity has profound consequences for economic theory and for econometric practice (4) Microeconometrics has contributed substantially to the scientific evaluation of public policy

https://www.jstor.org/stable/10.1086/322086

Micro Data, Heterogeneity, and the Evaluation of Public Policy: Nobel Lecture

This paper analyzes the specification and identification of causal multivariate duration models. We focus on the case in which one duration concerns the point in time a treatment is initiated and we are interested in the effect of this treatment on some outcome duration. We define “no anticipation of treatment” and relate it to a common assumption in biostatistics. We show that (i) no anticipation and (ii) randomized treatment assignment can be imposed without restricting the observational data. We impose (i) but not (ii) and prove identification of models that impose some structure. We allow for dependent unobserved heterogeneity and we do not exploit exclusion restrictions on covariates. We provide results for both single-spell and multiple-spell data. The timing of events conveys useful information on the treatment effect.

The nonparametric identification of treatment effects in duration models

Stratified partial likelihood estimation.

The paradigm of a rational individual acting on the earnings-enhancing benefits of migration is subjected to statistical scrutiny, using data from Turkey. Results with robust selectivity correction support the rationality hypothesis: Both migrants and nonmigrants chose the option in which they had comparative advantage. However, the estimated gain from moving is negative for a substantial portion of migrants, whereas a minority realize very high returns. This suggests that migration is a lottery: Individuals are willing to invest in a proposition that has a high probability of yielding negative returns because of the potential for a very large payoff.

Rationality of Migration

This paper presents a comparative study of private returns to schooling of urban men in Egypt, Iran, and Turkey using similar survey data and a uniform methodology. We employ three surveys for each country that span nearly two decades, from the 1980s to 2006, and, to increase the comparability of the estimates across surveys, we focus on urban men 20–54 years old and in full time wage and salary employment. Our aim is to learn how the monetary signals of rewards that guide individual decisions to invest in education are shaped by the institutions of education and labor markets in these countries. Our estimates generally support the stylized facts of the institutions of education and labor markets in Middle Eastern countries. Their labor markets have been described as dominated by the public sector and therefore relatively inflexible, and their education systems as more focused on secondary and tertiary degrees than teaching practical and productive skills. Returns in all countries are increasing in years ...

A comparative study of returns to education of urban men in egypt, iran, and turkey

This article offers an overview of aggregate migration flows in Turkey during 1963-73 and then develops models for explaining the qualitative and quantitative importance of various factors behind migration and remigration during 1963-73. The framework is based on the economic theories of migration that view geographic mobility as a response to differential earning opportunities distributed over time and across space. The analysis accounts for the impact of regional and macroeconomic variables on migration status while controlling for personal characteristics including migration history. The model uses a discrete choice formulation that accounts for consideration of remigration at the time of the initial migration decision. Migration status is assessed at the province district and village levels over 5- and 10-year intervals. The author uses six different definitions of migration. During 1950-80 Turkey experienced rapid urbanization and migration from economically backward areas to more dynamic areas usually in the western region. Data for the study were obtained from a sample of household heads from the male survey portion of the 1973 retrospective Survey of the Structure of Population and Population Problems. Findings indicate that undesirable work conditions in the sending area such as limited job opportunities lack of job-related security and unemployment plus human capital variables had a strong impact on the migration decision. The main finding is that regional and macroeconomic variables had a significant impact when individual heterogeneity was controlled for. It is argued that policy variables can reverse the impact of economic variables only by inducing extreme changes in the human capital variables. Migration policies should be directed at changing broad regional economic structures. Findings varied with the definition of migration and time. Results improved by distinguishing between return migrants and repeat migrants.

/pdf/migration-and-remigration-of-male-household-heads-in-turkey-1cppxcv03n.pdf

Migration and Remigration of Male Household Heads in Turkey, 1963-1973

SUMMARY Event data can often be analysed using different concepts of waiting time. Our application offers three choices: calendar-time, age, and duration of residence in New Orleans. We exploit the semi-parametric features of Cox regression and estimate parallel specifications in which mortality risk is treated as an arbitrary function of one of the three alternative time measures, while the remaining two enter the hazard parametrically. Comparisons of the parameter estimates with the corresponding estimates of the baseline hazards form the crux of a simple specification checking procedure. In our formal treatment we rely on Aalen's Multiplicative Intensity formulation and tackle complications such as left-truncation, functional form specification, and choice-based sampling. © 1997 by John Wiley & Sons, Ltd. J. appl. econom. 12: 1-25, 1997.

https://www.jstor.org/stable/pdfplus/2284897.pdf

Insan Tunali

Papers

Stratified partial likelihood estimation.

Rationality of Migration

A comparative study of returns to education of urban men in egypt, iran, and turkey

Migration and Remigration of Male Household Heads in Turkey, 1963-1973

Cox regression with alternative concepts of waiting time: the new orleans yellow fever epidemic of 1853