It is not easy for grad econ students to find out the themes of research. They are so busy in teaching that they can't study as they want.
I graduated from a graduate school of economics in 2005 and I re-started studying economics in 2007 and flied to a graduate school in the US, but returned here in 2008. Now I am in a teaching position at some private schools(not college or university) and trying to continue to study economics.
Recently I found a microeconomics book written by Takashi Negishi(1989), a worldly pioneer of general equilibrium theory: It has less than 250 pages and every item is written so shortly that I can follow. I try to read Chapter 4 on general equilibrium.
Until now I have tried several economics books and I found it difficult to understand economics by using them. Professor Maddala of Ohio State, they say, once said, "you can't learn anything from a fat book", and now I should completely agree with him.
I have tried to select a couple of econ texts(Micro: Varian(1992) and Dixit(1990), Macro: Barro&SalaiMartin(2004),Romer(2006)) and to focus on them to study micro and macro. I had a lot of macro texts, Blanchard&Fischer(1989), Obstfeld&Rogoff(1996), Sargent(2004),Farmer(1993) and so on, but it was too much for me to study the basics of macroeconomics. At last I decided to sell all these books and said to myself, "don't read too much and think more yourself first".
Before I went to the US, I had an interest in international finance, currency union, exchange rate fluctuation and open-macroeconomic policy. But reading the related research papers, I found it important to study macroeconomics and tried to study Ramsey model(optimal growth theory/RBC model). And then continuing Ramsey model, I found it more important to study general equilibrium model and studied basic micro theory, consumer-producer theory and Walrasian competitive equilibrium. Finally studying general equilibrium, I found it much more important to research 'equilibrium' and '(static&dynamic) optimization', of which modern microeconomics consists.
One day I was told one book by Prof Drewianka of Wisconsin Milwaukee and I tried to read it after I came back here. It was Schelling(1978), Micromotives and Macrobehavior, that I found interesting: Not too much but should be careful to read in order not to miss important ideas. It researches individual optimizations and social equilibria, and more on the related socio-economic matters. Reading it, I found it much more important to study the inter-relationship between micro optimizations and macro equilibria(phenomena) when I try to research some basic but difficult-to-understand macro issues, the determinations of interest rate, prices, exchange rate and national income.
Now I try to write plainly the interaction of agent behaviors and macro phenomena by using two key elements of modern economics(optimization and equilibrium) by using some related researches, Becker&Murphy(2000) and modern classics Akerlof(1984). Through basic study on economics, I would like to understand macro behaviors that have attracted social interests among people. I don't know how many years it takes to write it but I believe it is very important to keep trying.