tailieunhanh - Quantitative Techniques for Competition and Antitrust Analysis by Peter Davis and Eliana Garcés_9

Tham khảo tài liệu 'quantitative techniques for competition and antitrust analysis by peter davis and eliana garcés_9', khoa học xã hội, kinh tế chính trị phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | . Directly Identifying the Nature of Competition 303 contrast we will usually be able to observe the so-called reduced-form effect that is the aggregate effect of the movement theexogettoas variables the equilibrium market outcomes price quantity . The reduced-form effects will tell US how exogenous changes in demandandcosn doicriieaaiits affect marketenuilibrinm outcomes but we will only be ableto trace bnckfiieaatualpiffematers or ilo nmiead and supply functions in particularciraumotaoces. Let us assume the following den-íiriilecns-he ldequati riSiWhcre Ị red a arc the set of shifters of the demandandoepptyaoone res ctiaatyal timet Demand Qt a suppid. mi a Further let US assume that there is one demand shifter xt and one supply shifter wt so that p and ast c22wt uC. The supply-and-demand systemaaathenbawritteouitoe rotlowindmattixfoem 1 12 1 22 Qt Pt ll 0 0 C22 wt s ust Let yt Qt. Pt be the vector of endogenous variables and zt Xt wt the vector of exogenous variables in the form oMeme d and cosr shifters which are not determined by the system. We can write e structural system in file form Ăyt czt ut where A 1 1 12 ntn 022 and c 11 0 0 e22 and Ut is a vector of shocks Wf M Ms The reduced-form equations reaate thn vearor af rndsgenous variables to the exogenous variables and these can be obtained by inverting the 2 D D maffix A and performing some basic matrix algebra yt .I nr . . . Let us define C and A hdff tMioorkaewe canwrite the aeduced form as yt nzt Vf. Doing so gives an equation for eacholffhdendogenous Variables on the tofe-hand ne about the parameters in n. In particular we can learn about the parameters uling changes in zt the exogenous vr-hdleeakeclmg elthaa heda-y orWrmand. 304 6. Identification of Conduct Conditions for Identification of Pricing Equations The important question for identification is whether we can learn about the underlying structural parameters tn the strueturalequatiens of supply and demand equations.