A comparison of walk-in counselling and the wait list model for delivering counselling services

Background: Walk-in counselling has been used to reduce wait times but there are few controlled studies to compare outcomes between walk-in and the traditional model of service delivery. Aims: To compare change in psychological distress by clients receiving services from two models of service delivery, a walk-in counselling model and a traditional counselling model involving a wait list Method: Mixed methods sequential explanatory design including quantitative comparison of groups with one pre-test and two follow ups, and qualitative analysis of interviews with a subsample. 524 participants 16 years and older were recruited from two Family Counselling Agencies; the General Health Questionnaire assessed change in psychological distress; prior use of other mental health and instrumental services was also reported. Results: Hierarchical linear modelling revealed clients of the walk-in model improved faster and were less distressed at the 4-week follow-up compared to the traditional service delivery model. At the 10-week follow-up, both groups had improved and were similar. Participants receiving instrumental services prior to baseline improved more slowly. Qualitative interviews confirmed participants valued the accessibility of the walk-in model. Conclusions: This study improves methodologically on previous studies of walk-in counselling, an approach to service delivery that is not conducive to randomized controlled trials

Estimating the Gains From Trade in Limit Order Markets

We present a method for identifying and estimating the gains from trade in limit order markets and provide new empirical evidence that the limit order market is a good market design. The gains from trade in our model arise because traders have different valuations for the stock. We use observations on the traders’ order submissions and the execution and cancellation histories of the traders’ order submissions to estimate the distribution of traders’ unobserved valuations for the stock. We use the parameter estimates for our model to compute the current gains from trade in the limit order market and the gains from trade that the traders would attain in a perfectly liquid market.allocative efficiency; discrete choice; gains from trade; limit order markets

Liquidity Supply and Demand in Limit Order Markets

We model a trader’s decision to supply liquidity by submitting limit orders or demand liquidity by submitting market orders in a limit order market. The best quotes and the execution probabilities and picking off risks of limit orders determine the price of immediacy. The price of immediacy and the trader’s willingness to pay for immediacy determine the trader’s optimal order submission, with the trader’s willingness to pay for immediacy depending on the trader’s valuation for the stock. We estimate the execution probabilities and the picking off risks using a sample from the Vancouver Stock Exchange to compute the price of immediacy. The price of immediacy changes with market conditions — a trader’s optimal order submission changes with market conditions. We combine the price of immediacy with the actual order submissions to estimate the unobserved arrival rates of traders and the distribution of the traders’ valuations. High realized stock volatility increases the arrival rate of traders and increases the number of value traders arriving — liquidity supply is more competitive after periods of high volatility. An increase in the spread decreases the arrival rate of traders and decreases the number of value traders arriving — liquidity supply is less competitive when the spread widens.discrete choice; high frequency data; limit orders; liquidity; market orders