Markov analysis of land use change: Continuous time and stationary processes

In an earlier paper one of the authors has used actual land use maps to establish the validity of the Markov process for describing and projecting land use changes. In a subsequent paper the same data was used to calibrate a non-homogeneous, birth and death process in which the land uses were dichotomized into either of two states: developed or undeveloped. The present paper pursues two aspects raised by the earlier ones: whether the process of land use changes can be considered a stationary process and, if so, whether it can be fit by a continuous-time, rather than discrete-time, model. Necessary and sufficient conditions for the existence of a feasible fit are indicated.     

Over the moon or sick as a parrot? The effects of football results on a club's share price

This article considers the impact of match results on the stock returns of English football clubs. We propose that the magnitude of the response to a given result depends on the importance of the game, which is measured in two ways. First, we consider the extent to which the clubs are close rivals vying for similar league positions, as winning such games is particularly significant. Second, we argue that each individual game becomes more important for those clubs likely to be promoted or relegated as the season draws to a close, since a given match will have increasing information content concerning the final league position of the club. Using a fairly large panel comprising data for 19 clubs, we find some support for the notion that stock prices are affected more by the results of important matches than matches of lesser importance. We also observe that the difference between the number of points the club secures from a given match, and the number it was expected to secure, affects its stock price, as does the number of goals that the club under question scores in the match, relative to its competitor.     

Calculating long-run impacts of social programs with staggered implementation

When measuring the causal impacts of policy interventions, evaluators often contrast samples with and without the intervention tracked longitudinally. This article considers what happens when the without-intervention portion of the sample begins to be treated with the intervention part way through the follow-up period. The authors focus on randomized control trials, whose sponsors increasingly guarantee all participants in the study the intervention—the control members with a lag—while noting that the problem and their proposed solution apply to non-experimental impact evaluations as well. Once the control group (or other counterfactual group) receives the intervention, the treatment-control comparison becomes a measure of the difference in impacts between interventions of different durations—longer in the treatment group than the control group—rather than a measure of the total impact of the longer duration compared to no intervention. To measure this total impact—which tends to matter more to policy than differential or short-term impacts—the authors propose to sum the available experimental impact estimates from consecutive time periods, thus combining an experimental measure of the impact of the short duration intervention with an incremental measure of the added impact of the longer duration. The statistical properties of this estimator are explored, as are the conditions under which it provides an unbiased estimate of the total long-term effects of treatment.     

The Principles of Economics from Now until Then

Using the Economics U$A television series, the authors conducted an experiment to test whether course length and concentration affect learning.     

Regions of the Production Function,Returns, and Economies of Scale: A Reply

The author discusses a pedagogical strategy based on data visualization and analysis in the teaching of intermediate macroeconomics and financial economics. In these short projects, students collect and manipulate economic data from the online Federal Reserve Economic Database (FRED) in order to illustrate theoretical relationships discussed in class. All the data collection and manipulation tasks are conducted through the FRED Web site. The author argues that as students locate and effectively use the quantitative information that they need to evaluate abstract concepts, they are in effect developing the connection between theories and empirical evidence that underpins the discipline of economics.