About Richard

I currently study economics in Stockholm. Yes, that's it. ;)

Replacing KDE’s Kontact with Mozilla Thunderbird

Why would you want to do that? IMHO, by now the question is rather why you would want to continue using Kontact for your email/calendar/contact management needs given all the bugs and regressions. For example, after upgrading to KDE 4.8 on my Gentoo machine recently, once again address completion when composing emails ceased to work (it worked some time with 4.7.x, but not before that). Also, every now and then the virtuoso process consumed 100% CPU on login.

I had problems with KDEPIM2 ever since it was released (version 4.6.x), but was reluctant to ditch it since I had been a happy user for more than 5 years. Furthermore, KDEPIM is more powerful than Thunderbird. Nevertheless, this is 2012 and I am no longer willing to invest considerable time to have a working email and calendar solution. Maybe it works if you clean everything akondadi-, nepomuk- and kontact-related on each upgrade, but this is just not a viable option.

Anyway, to replace Kontact with Thunderbird there are several tweaks to make Thunderbird resemble the behavior of Kontact:

  1. Kmail, Akregator and KNode can be replaced by Thunderbird’s Email, Blogs & News Feeds and Newsgroup accounts, respectively. They may not be as powerful as the original programs, but they do their job.
  2. The KDE calendar is best replaced by the Lightning add-on. For remote synchronization, you will need something like the Provider for Google Calendar add-on. This works reasonably well.

Some additional useful add-ons that make Thunderbird behave like Kmail:

  1. SendWithoutSubject, otherwise there is a confirmation popup every time you try to send an email without a subject (you need an add-on for this, seriously?)
  2. Subject cleaner to eliminate repeated Re: Re:, etc. from subjects when replying (KMail does this automatically)
  3. Sieve to manage sieve scripts on your IMAP server, if you use those.
  4. ThunderPlunger is a useful add-on if you happen to delete accounts, because Thunderbird does not actually remove the data from disk, potentially leaving you with hundreds of megabytes of junk.
  5. LookOut is required to deal with those infamous winmail.dat files brought to you by MS Outlook’s proprietary handling of attachments.
  6. StartupMaster is a useful addon to eliminate multiple password prompts if you have a master password for the builtin password manager. This happens because the Google Calendar provider prompts for a password for each account.
    Update: For KDE users, the kwalltet password integration addon seems to be the way to go.

KMail also automatically checks all folders on your IMAP server, while Thunderbird does this only for the currently open folder. To mimic KMail’s behaviour you have to set
mail.server.default.check_all_folders_for_new
to true in the config editor.

Of course Thunderbird is not as nicely integrated into your desktop as Kontact. For example, I have yet to find a solution to display a systray icon with the number of unread mails, since solutions such as the Gnome integration add-on do not seem to work with the current version of TB. Also your calendar events are not displayed in the KDE Plasma calender if you decide to get rid of Akonadi completely.

Finally finished my diploma thesis…

It took some time, but today I finally managed to proofread my diploma thesis in economics (which is similar to a master’s thesis) titled “Endogenous growth in heterogeneous-firm trade models.”

Abstract: This thesis aims to demonstrate how a heterogeneous-firm trade and growth model can be used to analyze productivity and welfare effects of trade liberalization. To this end, I first discuss the evolution of trade and growth theories that culminated in a class of comprehensive models capable of accounting for phenomena that are deemed important by both trade and growth theorists. Focusing on one of these models, Gustafsson and Segerstrom (2010), I extend their comparative static analysis to out-of-steady-state dynamics and show that the presence of heterogeneous firms introduces nontrivial complications absent from homogeneous-firm models. Lastly, I present Gustafsson and Segerstrom’s main finding that knowledge spillovers play a pivotal role in determining whether trade liberalization is welfare increasing.

You can download the complete thesis here (PDF, 2.1 MB).

Dynamics in the Solow-Swan growth model

Another Mathematica demonstration: this one visualizes the comparative statics as well as the adjustment dynamics resulting from a parameter change in the Solow-Swan growth model.

I took professor Sorger‘s advanced macro class on growth and business cycle theories last semester, so I noticed that some textbooks (such as Barro/Sala-i-Martin) don’t show the adjustment process of capital, per-capita output, consumption, etc. I think it helps intuition to visualize these variables, which is why I created this demonstration.

You can download the Mathematica notebook (you’ll need either Mathematica or the free Mathematica player to view this), or look at the online version here. (Unfortunately Wolfram changed the demo so only one graph is visible at a time.)

Mathematica demonstration illustrating Melitz’ trade model

Melitz, again. I took a Mathematica class this semester where we had to build a demonstration that could be uploaded to Wolfram’s demonstration project site. I created an animated version of figure 2 from Melitz’ paper (based on the calculations done in one of the Mathematica notebooks presented below), which IMO is well suited to do a comparative statics analysis of autarky and the open economy.

The online demonstration is available here.

Melitz’ heterogeneous firm trade model with Pareto-distributed productivity

The Melitz (2003) trade model is one of the central models of my diploma thesis, so I’ve spent (wasted?) some time derived a closed-form solution for Pareto-distributed firm productivity levels (Melitz himself does not use a particular distribution).  I’ve been able to replicate most of paper’s results, while a few do not hold for the Pareto distribution (using other distributions, though, will generally not produce closed-form solutions). With the Mathematica notebook it is easy to manipulate model parameters and see the effects on equilibrium values.

Download links:  PDF, Mathematica Notebook (ZIP archive)

Update (Dec. 8, 2009): minor changes and error corrections in PDF and Mathematica notebook.

Update (Dec. 14, 2009): Helpman/Melitz/Yeaple (2004) present a similar model with heterogeneous firms and Pareto-distributed firm productivity. It is less complex than Melitz (2003) as it omits the stochastic firm entry and exit process. However, it allows to model firm decisions concerning production for the domestic market and export / FDI in foreign markets depending on firm productivity. The Mathematica notebook below derives this model in greater detail than the original paper.

Download links: PDF, Mathematica notebook/package

References:

  • Helpman, Elhanan/ Melitz, Marc J. and Yeaple, Stephen R. (2004): Export versus FDI with Heterogeneous Firms . In: American Economic Review 94(1), 300 316.
  • Melitz, Marc J. (2003): “The Impact of Trade on Intra-Industry Reallocations and Aggregate Industry Productivity”. In: Econometrica 71(6), 1695.

An idiot’s guide to Dixit/Stiglitz

While researching for my current diploma thesis on “new new” trade theory I realized that fully understanding (or rather: knowing by heart) the Dixit/Stiglitz (1977) model is a necessary precondition to be able to read most of the relevant papers. Unfortunately, the original Dixit/Stiglitz is not written for undergraduate students (intermediate steps are mostly omitted), and the obsolete Chamberlinian terminology does not exactly promote understanding (obsolete by Austrian university standards, that is).

Consequently I’ve compiled this step-by-step walkthrough of the first and most widely used model (the CES case) covered in Dixit/Stiglitz (1977). This should be sufficient for  most of the “new” and “new new” trade theory models. You can download it here.

Please let me know if you find any mistakes.

Update (Dec. 21, 2009): Minor corrections.

References:

  • Dixit, Avinash K. and Stiglitz, Joseph E. (1977): “Monopolistic Competition and Optimum Product Diversity”. In: American Economic Review 67(3), 297–308.

I guess this looks like a blog, but I won’t be using it as one. I see little value in further polluting the internet by sharing my thoughts on this or that. After all, I am not Paul Krugman or Brad DeLong, so why should anyone care? 😉 However, I will occasionally post stuff concerning my studies which other economics students might find useful.