We identify some of the factors affecting the extent of commonality in liquidity and differences between different stock exchanges around the world. With a comprehensive approach, our investigation centers on presenting evidence on the existence of commonality in liquidity, effect of using different measures of market variables on the level of commonality, factors that change the likelihood of stocks having commonality and factors explaining the different levels of commonality across markets. For the individual stock liquidity, we employ most common and reliable liquidity measures including quoted bid and ask spread, proportional spread, effective spread, proportional effective spread and percentage spread. For the market liquidity, we calculate the equal weighted and value weighted averages of the individual stock liquidity measures. Our base model of commonality of liquidity is an extension of Chordia, Roll, and Subrahmanyam (2000). Our data includes 36,457 common stocks in 46 stock exchanges in 33 countries. Our data period begins on January 2000 and covers until the end of December 2007. Our results show that 14.38% of all stocks in the world have commonality in liquidity with their markets when equally weighted market variables are used. This percentage drops to 9.76% with using value weighted market variables. After controlling for commonality in certain days of the week, we find that commonality is, in most part, uniformly distributed across days-of-the-week, almost for all countries. We also find that market factors including average spread, average price, average return, average risk, average size, legal system (common vs. civil law) and distribution of mean company size affect the likelihood of companies having commonality within their exchanges. In terms of the different levels across countries, we find that average percentage spread, level of risk, distribution of mean company size and legal system all have significant effects. Our results contribute to the literature analyzing factors that affect the level of commonality and types of companies that are likely to have commonality. Our study also has practical implications for portfolio diversification by providing evidence for possible reasons for common liquidity movements in the markets which may eventually lead to market liquidity crunches.

The shortcomings of the proportion above cut (PAC) statistic used so prominently in the educational landscape renders it a very problematic measure for making correct inferences with student test data. The limitations of PAC-based statistics are more pronounced with cross-test comparisons due to their dependency on cut-score locations. A better alternative is using mean-based statistics that can translate to parametric effect-size measures. However, these statistics as well can be problematic. When Gaussian assumptions are not met, reasonable transformations of a score scale produce non-monotonic outcomes. The present study develops a distribution-wide approach to summarize trend, gap, and gap trend (TGGT) measures. This approach counters the limitations of PAC-based measures and mean-based statistics in addition to addressing TGGT-related statistics in a manner more closely tied to both the data and questions regarding student achievement. This distribution-wide approach encompasses visual graphics such as percentile trend displays and probability-probability plots fashioned after Receiver Operating Characteristic (ROC) curve methodology. The latter is framed as the P-P plot framework that was proposed by Ho (2008) as a way to examine trends and gaps with more consideration given to questions of scale and policy decisions. The extension in this study involves three main components: (1) incorporating Bayesian inference, (2) using a multivariate structure for longitudinal data, and (3) accounting for measurement error at the individual level. The analysis is based on mathematical assessment data comprising Grade 3 to Grade 7 from a large Midwestern school district. Findings suggest that PP-based effect sizes provide a useful framework to measure aggregate test score change and achievement gaps. The distribution-wide perspective adds insight by examining both visually and numerically how trends and gaps are affected throughout the score distribution. Two notable findings using the PP-based effect sizes were (1) achievement gaps were very similar between the Focal and Audit test, and (2) trend measures were significantly larger for the Audit test. Additionally, measurement error corrections using the multivariate Bayesian CTT approach had effect sizes disattenuated from those based on observed scores. Also, the ordinal-based effect size statistics were generally larger than their parametric-based counterparts, and this disattenuation was practically equivalent to that seen by accounting for measurement error. Finally, the rank-based estimator of P(X>Y) via estimated true scores had smaller standard errors than for its parametric-based counterpart.

Qualitative and quantitative research methods were used to study instances of sudden gains within the case load of a private practice practitioner. Five clients whose progress was marked by such changes were contrasted with the views of five clients whose progress was marked by significant setbacks. Results from the quantitative analyses indicated that clients who experienced sudden gains during therapy tended to retain their therapeutic gains over a 2-year time period. In contrast, individuals who experienced setbacks in therapy generally continued to be distressed at the 2-year reassessment. Clients who experienced sudden gains were more distressed prior to treatment and were more satisfied with their experience looking back. A stronger working alliance was found amongst those who experienced sudden gains, although there was no difference between the groups' ratings regarding the strength of the therapeutic bond. Qualitative results suggested that therapy was helpful in bringing about many changes in clients' lives, but clients who experienced sudden gains generally recalled more positive aspects of therapy, demonstrated greater utilization of therapeutic techniques, endorsed more long-term changes, accepted more responsibility for their treatment outcomes, and were less likely to react negatively to therapeutic techniques. Clients who experienced setbacks in therapy were generally less optimistic about the future, felt that they had regressed since termination, and demonstrated more resistance to therapeutic techniques.