London School of Economics and Political Science

About: London School of Economics and Political Science is a education organization based out in London, United Kingdom. It is known for research contribution in the topics: Politics & Population. The organization has 8759 authors who have published 35017 publications receiving 1436302 citations.

Determining Benefits and Costs for Future Generations

Abstract: In economic project analysis, the rate at which future benefits and costs are discounted relative to current values often determines whether a project passes the benefit-cost test. This is especially true of projects with long time horizons, such as those to reduce greenhouse gas (GHG) emissions. Whether the benefits of climate policies, which can last for centuries, outweigh the costs, many of which are borne today, is especially sensitive to the rate at which future benefits are discounted. This is also true of other policies, e.g., affecting nuclear waste disposal or the construction of long-lived infrastructure.

Channeling Fisher: Randomization Tests and the Statistical Insignificance of Seemingly Significant Experimental Results

Abstract: I follow R. A. Fisher's The Design of Experiments (1935), using randomization statistical inference to test the null hypothesis of no treatment effects in a comprehensive sample of 53 experimental papers drawn from the journals of the American Economic Association. In the average paper, randomization tests of the significance of individual treatment effects find 13\% to 22\% fewer significant results than are found using authors’ methods. In joint tests of multiple treatment effects appearing together in tables, randomization tests yield 33\% to 49\% fewer statistically significant results than conventional tests. Bootstrap and jackknife methods support and confirm the randomization results.

The Effects of Minimum Wages on Employment: Theory and Evidence from the Us

Abstract: Recent work on the economic effects of minimum wages has stressed that the standard economic model, where increases in minimum wages depress employment, is not supported by the empirical findings in some labour markets. In this paper we present a theoretical framework which is general enough to allow minimum wages to have the conventional negative impact on employment, but which also allows for the possibility of a neutral or a positive effect. The model structure is based on labour market frictions which give employers some degree of monopsony power. The formulated model has a number of empirical implications which we go on to test using data on industry-based minimum wages set by the UK Wages Councils between 1975 and 1990. Some strong results emerge: minimum wages significantly compress the distribution of earnings and, contrary to conventional economic wisdom but in line with several recent studies, do not have a negative impact on employment. If anything, the relationship between minimum wages and employment is estimated to be positive.

Attracting investor attention through advertising

Abstract: This paper provides empirical evidence that managers adjust rm advertising expenditures to inuence investor behavior and short-term stock prices. First, this paper shows that increased

Revisiting Event Study Designs

Abstract: A broad empirical literature uses "event study" research designs for treatment effect estimation, a setting in which all units in the panel receive treatment but at random times. We make four novel points about identification and estimation of causal effects in this setting and show their practical relevance. First, we show that in the presence of unit and time fixed effects, it is impossible to identify the linear component of the path of pre-trends and dynamic treatment effects. Second, we propose graphical and statistical tests for pre-trends. Third, we consider commonly-used "static" regressions, with a treatment dummy instead of a full set of leads and lags around the treatment event, and we show that OLS does not recover a weighted average of the treatment effects: long-term effects are weighted negatively, and we introduce a different estimator that is robust to this issue. Fourth, we show that equivalent problems of under-identification and negative weighting arise in difference-in-differences settings when the control group is allowed to be on a different time trend or in the presence of unit-specific time trends. Finally, we show the practical relevance of these issues in a series of examples from the existing literature, with a focus on the estimation of the marginal propensity to consume out of tax rebates.