Lars P. Syll

The insignificance of significance A significance test is a scientific instrument, and like any other instrument, it has a certain degree of precision. If you make the test more sensitive—by increasing the size of the studied population, for example—you enable yourself to see ever-smaller effects. That’s the power of the method, but also its danger. The truth is, the null hypothesis, if we take it literally, is probably just about always false. When you...

Werden wir immer dümmer? .[embedded content]

The trickle down scam The empirical literature on the impact of corporate taxes on economic growth reaches ambiguous conclusions: corporate tax cuts increase, reduce, or do not significantly affect growth. We apply meta-regression methods to a novel data set with 441 estimates from 42 primary studies. There is evidence for publication selectivity in favour of reporting growth-enhancing effects of corporate tax cuts. Correcting for this bias, we cannot...

Why I am not a Bayesian Assume you’re a Bayesian turkey and hold a nonzero probability belief in hypothesis H that “people are nice vegetarians that do not eat turkeys and that every day I see the sun rises confirms my belief.” For every day you survive, you update your belief according to Bayes’ Rule P(H|e) = [P(e|H)P(H)]/P(e), where evidence e stands for “not being eaten” and P(e|H) = 1. Given that there do exist other hypotheses than H, P(e) is less than...

What to do about the present inflation To be sure, some normalization of interest rates would be a good thing. Interest rates are supposed to reflect the scarcity of capital, and the “correct” price of capital obviously is not zero or negative – as near-zero interest rates and very negative real (inflation-adjusted) interest rates would seem to imply. But there are substantial dangers in pushing rates too high, too fast. For example, it is important to...

Heckman on where causality resides I make two main points that are firmly anchored in the econometric tradition. The first is that causality is a property of a model of hypotheticals. A fully articulated model of the phenomena being studied precisely defines hypothetical or counterfactual states. A definition of causality drops out of a fully articulated model as an automatic by-product. A model is a set of possible counterfactual worlds constructed under...

.[embedded content]

Econometrics — nothing but a second-best explanatory practice Consider two elections, A and B. For each of them, identify the events that cause a given percentage of voters to turn out. Once we have thus explained the turnout in election A and the turnout in election B, the explanation of the difference (if any) follows automatically, as a by-product. As a bonus, we might be able to explain whether identical turnouts in A and B are accidental, that is, due...

Uber — the ugly truth .[embedded content]

Mainstream economics — the triumph of ideology over science Research shows not only that individuals sometimes act differently than standard economic theories predict, but that they do so regularly, systematically, and in ways that can be understood and interpreted through alternative hypotheses, competing with those utilised by orthodox economists. To most market participants — and, indeed, ordinary observers — this does not seem like big news … In fact,...