Susumu Imai joined the Economics Discipline Group in January 2013. He has received his PhD in economics from the University of Minnesota in 1998 and has held an academic position at the Pennsylvania State University, Concordia University and Queen's University.
Please visit his personal website.
Can supervise: YES
Empirical Labor Economics, Empirical Industrial Organization, Empirical Trade, Bayesian Econometrics.
Fallesen, P., Geerdsen, L.P., Imai, S. & Tranæs, T. 2018, 'The effect of active labor market policies on crime: Incapacitation and program effects', Labour Economics, vol. 52, pp. 263-286.View/Download from: Publisher's site
© 2018 We estimate the effects of active labor market policies on men's crime. To do this, we exploit a local policy change in Denmark that targeted unemployed people without unemployment insurance. Our results show that crime rates decreased among treated men relative to both untreated unemployment insured and uninsured men. Lower property crime accounted for the decrease in overall crime. Increased earnings from higher employment rates cannot explain the decrease in crime. Instead, participation in the active labor market program reduced young men's propensity to commit crime. The results suggest that active labor market programs have substantial secondary effects on criminality.
Heinesen, E., Imai, S. & Maruyama, S. 2018, 'Employment, job skills and occupational mobility of cancer survivors.', Journal of health economics, vol. 58, pp. 151-175.View/Download from: Publisher's site
Previous studies find significant negative effects of cancer on employment, with stronger effects for less-educated workers. We investigate whether the effect of cancer varies by skill requirement in the pre-cancer occupation, whether such heterogeneity can explain educational gradients, and whether cancer is associated with changes in job characteristics for cancer survivors who remain employed four years after the diagnosis. We combine Danish administrative registers with detailed skill requirement data and use individuals without cancer as a control group. Our main findings are the following: the negative effect of cancer on employment is stronger if the pre-cancer occupation requires high levels of manual skills or low levels of cognitive skills; the educational gradient diminishes substantially if we allow the effects of cancer to also depend on pre-cancer skill requirements; and cancer is not associated with occupational mobility, indicating potential for policies that reduce labour market frictions for cancer survivors.
Byrne, D.P., Imai, S., Jain, N., Sarafidis, V. & Hirukawa, M. 2015, 'Identification and Estimation of Differentiated Products Model using Market Size and Cost Data'.View/Download from: Publisher's site
Imai, S., Katayama, H. & Krishna, K. 2013, 'A quantile-based test of protection for sale model', Journal of International Economics, vol. 91, no. 1, pp. 40-52.View/Download from: UTS OPUS or Publisher's site
This paper proposes a new test of the Protection for Sale (PFS) model by Grossman and Helpman (1994). Unlike existing methods in the literature, our approach does not require any data on political organization. We use quantile and IV quantile regressions in our tests, using the data from Gawande and Bandyopadhyay (2000). Surprisingly, the results do not provide any evidence favoring the PFS model. We also explain why previous work may have found support for it.
Ching, A., Imai, S., Ishihara, M. & Jain, N. 2012, 'A practitioner's guide to Bayesian estimation of discrete choice dynamic programming models', Quantitative Marketing and Economics, vol. 10, no. 2, pp. 151-196.View/Download from: UTS OPUS or Publisher's site
This paper provides a step-by-step guide to estimating infinite horizon discrete choice dynamic programming (DDP) models using a new Bayesian estimation algorithm (Imai et al., Econometrica 77:18651899, 2009a) (IJC). In the conventional nested fixed point algorithm, most of the information obtained in the past iterations remains unused in the current iteration. In contrast, the IJC algorithm extensively uses the computational results obtained from the past iterations to help solve the DDP model at the current iterated parameter values. Consequently, it has the potential to significantly alleviate the computational burden of estimating DDP models. To illustrate this new estimation method, we use a simple dynamic store choice model where stores offer frequent-buyer type rewards programs. Our Monte Carlo results demonstrate that the IJC method is able to recover the true parameter values of this model quite precisely. We also show that the IJC method could reduce the estimation time significantly when estimating DDP models with unobserved heterogeneity, especially when the discount factor is close to 1.
Imai, S. 2009, 'The Inside Scoop: Acceptance and Rejection at the Journal of International Economics', Journal of International Economics, vol. 77, no. 1, pp. 120-132.View/Download from: UTS OPUS or Publisher's site
There is little work on the inner workings of journals. What factors seem to affect the ability to publish in a journal? Could simple rules (which are already used by some journals) like the desk rejection of a significant minority of papers, help to streamline the process? At what cost? How well do journals seem to do in choosing papers? What can we say about the extent of type 1 and type 2 errors? Do editors seem to have uniform standards or are some harsher than others? We use data on submissions to the Journal of International Economics to help answer these questions.
We propose a new methodology for structural estimation of infinite horizon dynamic discrete choice models. We combine the dynamic programming (DP) solution algorithm with the Bayesian Markov chain Monte Carlo algorithm into a single algorithm that solves the DP problem and estimates the parameters simultaneously. As a result, the computational burden of estimating a dynamic model becomes comparable to that of a static model. Another feature of our algorithm is that even though the number of grid points on the state variable is small per solution-estimation iteration, the number of effective grid points increases with the number of estimation iterations. This is how we help ease the curse of dimensionality. We simulate and estimate several versions of a simple model of entry and exit to illustrate our methodology. We also prove that under standard conditions, the parameters converge in probability to the true posterior distribution, regardless of the starting values.
Imai, S., Katayama, H. & Krishna, K. 2009, 'Is Protection Really for Sale? A Survey and Directions for Future Research', International Review of Economics and Finance, vol. 18, no. 2, pp. 181-191.View/Download from: UTS OPUS or Publisher's site
This paper critically and selectively surveys the literature on protection for sale and discusses directions for future research in this area. It suggests that the standard approach needs to be augmented to provide more compelling tests of this model.
This paper asks whether the results obtained from using the standard approach to testing the influential Grossman and Helpman protection for sale model of political economy might arise from a simpler setting. A model of imports and quotas with protection occurring in response to import surges, but only for organized industries, is simulated and shown to provide parameter estimates consistent with the protection for sale framework. This suggests that the standard approach may be less of a test than previously thought.
Imai, S., Cherkashin, I., Demidova, S. & Krishna, K. 2008, 'Evaluating Journal Performance using Inside Data', voxEU.org.
We solve and estimate a dynamic model that allows agents to optimally choose their labor hours and consumption and that allows for both human capital accumulation and savings. Estimation results and simulation exercises indicate that the intertemporal elasticity of substitution is much higher than the conventional estimates and the downward bias comes from the omission of the human capital accumulation effect. The human capital accumulation effect renders the life-cycle path of the shadow wage relatively flat, even though wages increase with age. Hence, a rather flat life-cycle labor supply path can be reconciled with a high intertemporal elasticity of substitution.
Coulson, E., Hwang, S. & Imai, S. 2003, 'The benefits of owner-occupation in neighvorhoods', Journal of Housing Research, vol. 14, no. 1, pp. 21-48.
Coulson, E., Hwang, S. & Imai, S. 2003, 'The value of owner-occupation in neighvorhoods', Journal of Housing Research, vol. 13, no. 2, pp. 153-174.
Erdem, T., Imai, S. & Keane, M. 2003, 'Brand and quantity choice dynamics under price uncertainty', Quantitative Marketing and Economics, vol. 1, no. 1, pp. 5-64.
Byrne, D.P., Imai, S., Sarafidis, V. & Hirukawa, M. 2015, 'Instrument-free Identification and Estimation of Differentiated Products Models'.
We propose a new methodology for estimating the demand and cost functions of differentiated products models when demand and cost data are available. The method deals with the endogeneity of prices to demand shocks and the
endogeneity of outputs to cost shocks, but does not require instruments for identification. We establish non-parametric identification, consistency and asymptotic normality of our estimator. Using Monte-Carlo experiments, we show our
method works well in contexts where instruments are correlated with demand and cost shocks, and where commonly-used instrumental variables estimators are biased and numerically unstable.
Imai, S., Stacey, D. & Warman, C. 2014, 'From Engineer to Taxi Driver? Language Proficiency and the Occupational Skills of Immigrants'.
We examine the ability of male immigrants to transfer the occupational human capital they acquired prior to immigration using information from the O*NET and a unique dataset that includes both the last source country
occupation and the first four years of occupations in Canada. We first augment a model of occupational choice to study the implications of language proficiency on the cross-border transferability of occupational human capital. We
then test the empirical predictions using the skill requirements of pre- and post-immigration occupations. We find that male immigrants to Canada were employed in source country occupations that required high levels of cognitive
skills, but relied less intently on manual skills. Following immigration, they find initial employment in occupations that require the opposite. These discrepancies are both larger and more detrimental to earnings among immigrants
with limited language fluency.
Fallesen, P., Geerdsen, L.P., Imai, S. & Tranæs, T., 'The Effect of Workfare on Crime: Incapacitation and Program Effects'.
In this paper, we estimate the effect of workfare policy on crime by exploiting two exogenous welfare policy changes in Denmark. Our results show a strong decline in the crime rate among treated unemployment uninsured men relative to untreated uninsured and unemployment insured men, and part of this decline can be identified as a direct effect of workfare participation. Moreover, we find that criminal activity was also reduced during weekends, when the workfare programs were closed, allowing us to distinguishing the pure program effect from the incapacitation effect. These results imply a strong and potentially lasting crime reducing effect of workfare policy.
Imai, S., Stacey, D. & Warman, C., 'From Engineer to Taxi Driver? Language Proficiency and the Occupational Skills of Immigrants'.
We examine the ability of immigrants to transfer the occupational human capital they acquired prior to immigration. We first augment a model of occupational choice to study the implications of language proficiency on the cross-border transferability of occupational human capital. We then test the empirical predictions using information about the skill requirements from the O*NET and a unique dataset that includes both the last source country occupation and the first four years of occupations in Canada. We supplement the analysis using Census estimates for the same cohort with source country occupation predicted using detailed human capital related information such as field of study. We find that male immigrants to Canada were employed in source country occupations that required high levels of cognitive skills, but relied less intently on manual skills. Following immigration, they find initial employment in occupations that require the opposite. Consistent with the hypothesized asymmetric role of language in the transferability of previously acquired cognitive and manual skills, these discrepancies are both larger and more detrimental to earnings among immigrants with limited language fluency.