 So guys, up till now, we have learned two major sections of international economics. In the first section, we learned trade and its related theories and in second section, we learned about the trade policies and how the trade policies are affecting the world and ultimately, how countries are interacting with each other by adopting different trade policies or in that particular section, related to trade policies, we studied from different angles that how trade is basically interlinking various countries and how through trade countries are growing over the period of time. And then in the last few modules, we have also seen how through trade, through developing countries' experiences, some countries have grown, some countries have not been able to take advantage of trade as such. Now in the third major section of international economics, we are moving towards national income and balance of payments and then exchange rate determination. Let's start with this. Primarily, in today's module or even in some coming modules, we will revise the concepts of national income if you have read the macroeconomic course before. And then we will look at the issues of balance of payment, which elements are major to balance of payment. So, principally, when we started this course, we discussed that how economics is concerned about the use of scare resources of the world and how these scare resources can be used productively for the world and specifically for our country. So, economics's idea was that how to use resources better and the major two branches of economics that was microeconomics and macroeconomics. Now, let's extend it a little bit from simple micro, broader microeconomics to international microeconomics. Principally, microeconomics, when you studied earlier, when you started studying economics, at that time, you just looked at consumer behavior, then firm behavior. But in the last few modules, or even from the start of this course, when we started this, basically, we discussed the micro level at the international level. So, we can say that we have learned international microeconomics to some extent. Principally, we have learned that in which way, using factor endowments in some countries, things are sent to the international level. And from there, they come into the country in the form of foreign exchange. And in which way, we cannot fulfill our needs domestically. So, from the international level, we get them in the form of different countries. So, in this case, we looked at individual production, we looked at commodities, we looked at production possibilities, we drew frontiers, then we looked at overall competitiveness, we looked at commodities, we talked about sectors, we talked about some labor intensive, we talked about capital intensive. Then, in the same way, on consumption decision, when we went into the form of equilibrium, when we read the different theories of the countries, then consumption and production intersected somewhere, then we gave it the name of equilibrium level. So, we have seen these things previously. Now, next, as you know, the base of macroeconomics is principally microeconomics. So, ultimately, now, our objective, some of the modules from here onward, which we have read a large section of international microeconomics, now we will go to international macroeconomics. Which principally deals with how different countries interact with each other, and ultimately, how their decisions can affect the rest of the word. Because until now, we have talked about microeconomics, so to some extent, we have discussed that there is a big economy and a small economy, and how their trade is. And to some extent, we have also discussed the macroeconomics, international macroeconomics. But here, what we are going to read now is basically the base of how a nation's identification is or recognition is at world level. As we are talking today, we say, you have a word, it is a unipolar, which, suppose, will be in the form of a bipolar, or even some people talk about a multipolar word. Unipolar means that it is only from the US that dominates the whole word. And then, a currently China is coming up as an economic power, so people are now looking at this unipolar word as a bipolar word. Now, behind this particular, which you have discussions, theories, or even which you have international media highlights, what is the theme behind this? On what basis we say that China, that is the next superpower, or word will become bipolar. So, behind this, economics has a big hand. Although, politically, socially, and economically, things are seen in all three angles. And then, different technological innovation, development concept, the concept of economics is also discussed. So, ultimately, the most traditional measure has always been the income. That is the base we will take here. And in particular, in some of the modules, we will discuss a little bit about national income, or those of you who are a GDP gross domestic product as a student of economics, you would have learned that and you would have heard at least. Or the concept of GNPs, of gross national products. So, we will start from here and then we will see how domestic incomes are, or how a nation connects with the rest of the world, which we call open economies. And we will give it to the net exports sector as well. We will see in the future, inshallah, in some coming modules. Now, our idea will be primarily, in some coming 8 to 10 modules, we will talk about a nation's GDP, and then we will talk about its connectivity through trade, and how a nation's standards are at different levels, at international levels. We will also discuss that as well, inshallah.