Mathias Lé’s research while affiliated with Paris School of Economics, French National Centre for Scientific Research and other places

Using 50,000 tests published in the AER, JPE, and QJE, we identify a residual in the distribution of tests that cannot be explained solely by journals favoring rejection of the null hypothesis. We observe a two-humped camel shape with missing p-values between 0.25 and 0.10 that can be retrieved just after the 0.05 threshold and represent 10-20 percent of marginally rejected tests. Our interpretation is that researchers inflate the value of just-rejected tests by choosing "significant" specifications. We propose a method to measure this residual and describe how it varies by article and author characteristics.

The Bankscope dataset is a popular source of bank balance sheet informations among banking economists, which covers the last 20 years for more than 30,000 worldwide banks. This technical paper intends to provide the critical issues one has to keep in mind as well as the basic arrangements which have to be undertaken if one intends to use this dataset. To that extent, we propose some straightforward ways to deal with data comparability, consolidation, duplication of assets or mergers, and provide Stata codes to deal with it.

Journals favor rejections of the null hypothesis. This selection upon results may distort the behavior of researchers. Using 50,000 tests published between 2005 and 2011 in the AER, JPE and QJE, we identify a residual in the distribution of tests that cannot be explained by selection. The distribution of p-values exhibits a camel shape with abundant p-values above :25, a valley between :25 and :10 and a bump slightly under :05. Missing tests are those which would have been accepted but close to being rejected (p-values between :25 and :10). We show that this pattern corresponds to a shift in the distribution of p-values: between 10% and 20% of marginally rejected tests are misallocated. Our interpretation is that researchers might be tempted to inflate the value of their tests by choosing the specification that provides the highest statistics. Note that Inflation is larger in articles where stars are used in order to highlight statistical significance and lower in articles with theoretical models.