Measuring the Impacts of Community Development Initiatives: A New Application of the Adjusted Interrupted Time-Series Method

The authors contribute to the development of empirical methods for measuring the impacts of place-based local development strategies by introducing the adjusted interrupted time-series (AITS) approach. It estimates a more precise counterfactual scenario, thus offering a stronger basis for drawing causal inferences about impacts. The authors applied the AITS approach to three community development initiatives using single-family home prices as the outcome indicator and found that it could measure impacts on both the base level of prices and the rate of price appreciation. The authors also found a situation in which the method appears unreliable, however. The AITS approach benefits from more recurrent data on outcomes during the pre-and post-intervention periods, with an intertemporal pattern that avoids great volatility. The AITS approach to measuring effects of community development initiatives holds strong promise, with caveats.