Let’s take again a look at Biontech / Pfizers vaccine candiate for which a press release stated more than 90% efficacy. As noted in my previous post Biontech/Pfizer actually use a Bayesian approach to assess the efficacy of their vaccine candiate. In ... [Read more...]

Probably, many of you have read the positive news from the Biontech/Pfizer press release from November 9th: “Vaccine candidate was found to be more than 90% effective in preventing COVID-19 in participants without evidence of prior SARS-CoV-2 infec... [Read more...]

Competition authorities regularly decide (and often defend in legal courts) whether to allow or forbid a merger, what fines to impose for illegal collusion, whether to restrict certain business practices of firms that have achieved a dominant position,... [Read more...]

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An exciting, quite new branch of econometrics studies how machine learning techniques can be adapted to consistently estimate causal effects. For example, the widely cited article by Belloni, Chernozhukov and Hansen (2014) introduces a post double sele... [Read more...]

My course Market Analysis with Econometrics and Machine Learning uses a lot of RTutor problem sets where students can solve interactive exercises with automatic hints and checks of their solutions. One can design RTutor problem sets to be solved in a ... [Read more...]

Econometrics does not cease to surprise me. I just now realized an interesting feature of the omitted variable bias. Consider the following model: Assume we want to estimate the causal effect beta of x on y. However, we have an unobserved confound... [Read more...]

Probably many of us would be more inclined to watch a particular movie in cinema if some friends or colleagues have already seen it and talk about it (at least if it is a decent movie). Duncan Sheppard Gilchrist and Emily Glassberg Sands quantify such... [Read more...]

So far, my main source of information about the US justice system have been tv shows like Suits, or The Good Wife. They suggest that hiring yourself a good lawyer can be quite expensive but may have a big impact on the verdict. But that are tv shows. W... [Read more...]

Consider a regression model with the following causal structure: The variable x1 affects y directly and also indirectly via x2. The following R code implements the model and simulates a corresponding data set. set.seed(1) n = 10000 beta1 = 1; bet... [Read more...]

Almost a year is now gone since I posted my last update about my shiny-powered search app. It allows to search among currently more than 5000 economic articles that have an accessible data and code supplement: https://ejd.econ.mathematik.uni-ulm.de The main data for my app can be downloaded ... [Read more...]

In this Corona semester, I have created at Ulm University a new online course Market Analysis with Econometrics and Machine Learning. I put the course material on this Github repository but you can work through most of the course directly online. Shin... [Read more...]

One way by which carbon pricing can reduce CO2 emmissions is by shifting electricity production from coal power plants to natural gas plants. A combined cycle gas turbine emits roughly only half as much CO2 per MWh produced electricity than a coal powe... [Read more...]

Were there no Corona virus pandemic, German Universities would regularly start the summer semester in around a month (soon after Eastern). Now, it seems likely that courses will be offered digitally and students must learn from home. If you have a cou... [Read more...]

Based on Robert S. Mueller’s investigations about foreign involvement in the 2016 US presidential elections US Congress created this website with the title “Exposing Russia’s Effort to Sow Discord Online: The Internet Research Agency and Advertis... [Read more...]

This post continues my first post on game theoretic analysis with the package RelationalContacts in R. Here we look at more complex infinite horizon games with endogenous states. I also illustrate how one can explicitly combine relational contracting and hold-up concerns. The following code specifies a game with 3 states:

<span class="n">library</span><span class="p">(</span><span class="n">RelationalContracts</span><span class="p">)</span><span class="w">
</span><span class="n">g</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rel_game</span><span class="p">(</span><span class="s2">"Mutual Gift Game with Endogenous Vulnerability"</span><span class="p">)</span><span class="w"> </span><span class="o">%>%</span><span class="w">
  </span><span class="n">rel_param</span><span class="p">(</span><span class="n">vul</span><span class="o">=</span><span class="m">1</span><span class="p">,</span><span class="w"> </span><span class="n">delta</span><span class="o">=</span><span class="m">0.3</span><span class="p">)</span><span class="w"> </span><span class="o">%>%</span><span class="w">
  </span><span class="n">rel_state</span><span class="p">(</span><span class="s2">"x_0"</span><span class="p">,</span><span class="w">
    </span><span class="n">A1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nf">list</span><span class="p">(</span><span class="n">move</span><span class="o">=</span><span class="nf">c</span><span class="p">(</span><span class="s2">"vul"</span><span class="p">,</span><span class="s2">"not"</span><span class="p">)),</span><span class="w">
    </span><span class="n">pi1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">,</span><span class="w">
    </span><span class="n">pi2</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="w">
  </span><span class="p">)</span><span class="w"> </span><span class="o">%>%</span><span class="w">
  </span><span class="n">rel_transition</span><span class="p">(</span><span class="s2">"x_0"</span><span class="p">,</span><span class="s2">"x_not"</span><span class="p">,</span><span class="n">move</span><span class="o">=</span><span class="s2">"not"</span><span class="p">,</span><span class="n">prob</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">1</span><span class="p">)</span><span class="w"> </span><span class="o">%>%</span><span class="w">
  </span><span class="n">rel_transition</span><span class="p">(</span><span class="s2">"x_0"</span><span class="p">,</span><span class="s2">"x_vul"</span><span class="p">,</span><span class="n">move</span><span class="o">=</span><span class="s2">"vul"</span><span class="p">,</span><span class="n">prob</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">1</span><span class="p">)</span><span class="w"> </span><span class="o">%>%</span><span class="w">
  </span><span class="n">rel_state</span><span class="p">(</span><span class="s2">"x_not"</span><span class="p">,</span><span class="w">
    </span><span class="n">A1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nf">list</span><span class="p">(</span><span class="n">e1</span><span class="o">=</span><span class="n">seq</span><span class="p">(</span><span class="m">0</span><span class="p">,</span><span class="m">1</span><span class="p">,</span><span class="n">by</span><span class="o">=</span><span class="m">0.1</span><span class="p">)),</span><span class="w">
    </span><span class="n">A2</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nf">list</span><span class="p">(</span><span class="n">e2</span><span class="o">=</span><span class="n">seq</span><span class="p">(</span><span class="m">0</span><span class="p">,</span><span class="m">1</span><span class="p">,</span><span class="n">by</span><span class="o">=</span><span class="m">0.1</span><span class="p">)),</span><span class="w">
    </span><span class="n">pi1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">~</span><span class="w"> </span><span class="n">e2</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">0.5</span><span class="o">*</span><span class="n">e1</span><span class="o">^</span><span class="m">2</span><span class="p">,</span><span class="w">
    </span><span class="n">pi2</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">~</span><span class="w"> </span><span class="n">e1</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">0.5</span><span class="o">*</span><span class="n">e2</span><span class="o">^</span><span class="m">2</span><span class="w">
  </span><span class="p">)</span><span class="w"> </span><span class="o">%>%</span><span class="w">
  </span><span class="n">rel_state</span><span class="p">(</span><span class="s2">"x_vul"</span><span class="p">,</span><span class="w">
    </span><span class="n">A1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nf">list</span><span class="p">(</span><span class="n">e1</span><span class="o">=</span><span class="n">seq</span><span class="p">(</span><span class="m">0</span><span class="p">,</span><span class="m">1</span><span class="p">,</span><span class="n">by</span><span class="o">=</span><span class="m">0.1</span><span class="p">)),</span><span class="w">
    </span><span class="n">A2</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nf">list</span><span class="p">(</span><span class="n">e2</span><span class="o">=~</span><span class="nf">c</span><span class="p">(</span><span class="o">-</span><span class="n">vul</span><span class="p">,</span><span class="n">seq</span><span class="p">(</span><span class="m">0</span><span class="p">,</span><span class="m">1</span><span class="p">,</span><span class="n">by</span><span class="o">=</span><span class="m">0.1</span><span class="p">))),</span><span class="w">
    </span><span class="n">pi1</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">~</span><span class="w"> </span><span class="n">e2</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">0.5</span><span class="o">*</span><span class="n">e1</span><span class="o">^</span><span class="m">2</span><span class="p">,</span><span class="w">
    </span><span class="n">pi2</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">~</span><span class="w"> </span><span class="n">e1</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">0.5</span><span class="o">*</span><span class="n">pmax</span><span class="p">(</span><span class="n">e2</span><span class="p">,</span><span class="m">0</span><span class="p">)</span><span class="o">^</span><span class="m">2</span><span class="w">
  </span><span class="p">)</span><span class="w">
</span>

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The small new package glueformula with a single function gf facilitates constructing regression formulas from vectors with variable names. The syntax is similar to glue strings. Here is an example: # Example: build a formula # for ivreg with gf libra... [Read more...]

I just found out that here the EU made large data sets available about every newly registered car in the EU (currently from 2012 to 2018). The data set from 2018 has over 15 million rows and many rows correspond to a single registered car. The followi... [Read more...]