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1. Lecture 7Stephen G HallIDENTIFICATION
27. But we need to identify the target relationships from the space spanned by these cointegrating vectors.
We now illustrate this process
34. Irreducibility As an underlying concept for identification
35. Irreducible cointegrating vectors Davidson proposed the notion of irreducibility as a way of detecting and identifying structural relations.
An irreducible vector is one where you can not remove any variables without loosing cointegration
43. Conclusion If we want to understand structure identification is crucial
We now have the technology to identify both the long and the short run structure of a model
44. An ExampleBargaining models and identifying the wage equation. G Chamberlin, S G Hall,
and S G B Henry.
45. Introduction Standard models of wage determination have followed the bargaining framework for many years
Manning 1993 argued that the wage equation was not identified in this model
A major problem not resolved
46. Introduction this paper uses modern cointegration identification theory to argue that this view is wrong
It
Outlines identification
Outlines wage theory
Show how this identifies the wage equation
Apply these ides to the UK
47. The Manning problem Suppose the demand for employment is
Ed=f(x)
And supply is
Es=g(z)
Then a bargain over wages will result such that, the real wage w will be
W=h(x,z)
48. But problem The wage equation now contains all the variables in the system nothing is excluded
Hence it can not be identified by the standard order condition
49. The paper then outlines identification theory as earlier in this lecture
50. The key thing is that these restrictions are on the cointegrating vectors.
Not on the equations.
Nothing needs to be excluded from any equations to identify the long run
51. Bargaining theory Does the theory identify the long run relationships?
go back to the key paper in this area
McDonald Solow(1981) outline various cases
52. Case 1 Firm; Maximise Profits R (L)-wL
Union Maximise Utility L(U(w) - Un )
Which implies
R(L)-w=0
(U(w)-Un )/wU(w)+LR(L)/R(L)=0
2 cointegrating vectors
53. Case 2 This is a true bargaining model. A contract curve is derived
(U(w)-U(wr))/U(w) = w- R (L)
Which may imply
(U(w)-U(wr))/U(w) = B
w- R (L) = B
2 cointegrating relationships
54. The message The more structure or theory we can bring to bare on a problem the more likely we are to be able to properly identify the system we are interested in.
55. estimation We now estimate a model of the wage bargaining process in the UK.
We assume cobb-douglas technology and estimate both the production function, the marginal revenue condition and the labour supply condition
56. The core model
57. Stationarity tests
58. Weak exogeneity
59. Testing r
60. Model structure This gives us a 6-equation system to estimate with 3 long run relationships, which we hope to identify as the production function and the marginal product condition.
61. The estimated long run structure
62. The wage equation
63. Some tests of restrictions
64. conclusion The bargaining wage equation may be identified
We have outlined the theory of identification and bargaining
We have applied this with success to UK data.