دانلود کتاب اقتصاد کلان ۱: ناهمگنی، پویایی و رفاه

Macroeconomics is about aggregates. Aggregates must be constructed so as not to sacrifice relevant information relevant to the specific problems being addressed. Although it is often useful to know the size of the cake, it may sometimes be more enlightening to know how it is partitioned. However, macroeconomic modelling has long bypassed the aggregation problem by resorting to the devices of the representative agent and of the one-sector production system, or by contracting time to a single point. In other words, it has long portrayed how Robinson Crusoe manages his coconut endowment, on a single day between the shipwreck and Friday’s arrival. Interestingly, these shortcuts have not been largely exploited at the beginning of macroeconomic theorising, when economists were not yet trying to keep everything within an all-encompassing model. Keynes, for instance, took into account interacting agents and diversified goods in the loose model sketched in the General Theory. Also, these shortcuts, omnipresent for several decades, are no longer found in the frontiers of contemporary macroeconomics. Introducing multiple identical agents or identical sectors does not change much with respect to the representative agent and representative industry plain assumptions. What does change is taking agent and industry diversity into account. That is why it is natural to start with heterogeneity. The first three chapters of this volume deal with heterogeneity: (1) of agents, more specifically of households, as savers and spenders who differ in their time preferences over consumption and in their borrowing constraints; (2) of production sectors, which differ in their position in the production process (production of final, consumption, goods versus production of intermediate, investment, goods) and in their technological characteristics, namely their capital intensities; (3) of agents’ information, with focus on the ensuing problems of coordination between differently informed and strategically interacting agents.