Publications

This paper exploits the homogeneity feature of the Singapore private residential condominium market and constructs matched home purchase price and rental price series using the repeated sales method. These matched series allow us to conduct time series analysis to examine the long-term present value relationship in the housing market. Three key findings are obtained. First, we fail to establish a cointegrating relationship between the home purchase price and rental price based on nationally estimated indexes. Second, area-specific indexes demonstrate strong cross-correlations, invalidating the use of first generation panel unit root tests that ignore these cross-correlations. Third, Pesaran's CIPS test indicates that the unit root hypothesis is rejected for the first difference of both indexes. We also do not reject the hypothesis that area-specific home purchases and rental price indexes are cointegrated with a cointegrating vector (1, - 1).

This paper examines two factors that help to explain geographic variation in health outcomes. The first factor concerns proximity to medical services. The second factor is state-specific health care policy that may impede access to nearby medical services. Four key findings are obtained. First, the effect of local doctors on reducing mortality rates of various diseases in a county attenuates with distance. Second, at approximately the same distance, in-state doctors contribute more to lowering mortality rates in the primary county than do out-of-state doctors. Third, the lesser impact of nearby out-of-state doctors is further reduced when the primary state adopts more stringent policies that restrict entry of out-of-state physicians. Fourth, the impact of nearby doctors is found to be stronger in more urbanized areas. This is consistent with agglomeration economies being effective in contributing, at least in part, to the productivity of treating patients.

Holly, Pesaran, and Yamagata (Journal of Econometrics 2010; 158: 160–173) use a panel of 49 states over the period 1975–2003 to show that state-level real housing prices are driven by economic fundamentals, such as real per capita disposable income, as well as by common shocks, such as changes in interest rates, oil prices and technological change. They apply the common correlated effects estimator of Pesaran (Econometrica 2006; 74(4): 967–101), which takes into account spatial interactions that reflect both geographical proximity and unobserved common factors. This paper replicates their results using a panel of 381 metropolitan statistical areas observed over the period 1975–2011. Our replication shows that their results are fairly robust to the more geographically refined cross-section units, and to the updated period of study.

This paper addresses two related questions that help to explain geographic variation in access to medical services. The first question examines the existence of agglomeration economies in the hospital service industry. The second considers whether the sharing of intermediate inputs contributes to spillovers from spatial concentration of hospital services. These questions are addressed by estimating a bivariate probit model that explicitly controls for potential correlations between whether a service is provided and how the service is provided. Three key findings are obtained. First, hospitals in more concentrated areas are more likely to outsource intermediate services to specialized intermediate service suppliers. This suggests that agglomeration economies exist in the hospital service industry and are generated in part through the sharing of intermediate inputs. Second, the presence of nearby small hospitals increases the tendency to outsource, which is consistent with a “Chinitz” effect identified elsewhere in the literature. Third, the agglomeration effect attenuates geographically.