12' pdeata ta, formal models'

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12. ?p?de??µata (µ??t??a, formal models).
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?e??e??µe?? t?? µa??µat?? ?a? ß?ß?????af?a

• ?as??? ?a?a?t???st??? t?? µ??t????
  (?p?de??µ?t??) ?a?ad????, µa??µat??? d?at?p?s?,
  apa????.
• ??s? ?ea??st???? p??pe? ?a e??a? ?? pa?ad???? ?
  d???e?? Friedman Samuelson.
• ?a?ade??µata ap? t?? ??????µ??? ?a? p???t???
  ep?st?µ? (Downs, Olson ??p).
• ??ß?????af?a
• ?a?????, ?. ??????ta? t?? ???????a...., ?p??
  a????, ?ef??a?? 4, se?. 175-203, ?p?? ?a? s?et???
  ß?ß?????af?a.
• ??. ep?s?? Begg/ Fischer/ Dornbusch ??sa????
  st?? ??????µ???, e?d?se?? ???t???, ????a 1998
  (ta ?ef??a?a ??a t?? ??????µ??? µe??d?????a).

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• G?a eµß????s?
• Friedman, M. The methodology of positive
  economics, in Essays in positive economics,
  Chicago University Press, Chicago 1953 3-43 ?a?
  (t? apa?t?t???te??)
• Morton, Rebecca Methods and models. A guide to
  the empirical analysis of formal models in
  political science, Cambridge Univcersity Press,
  Cambridge 2005 (??a p??????µ?????).

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?ata????ta? µ??t??a µes?...a?e??d??.

• SOCIALISM You have 2 cows. You give
  one to your neighbour.
• COMMUNISM You have 2 cows. The State
  takes both and gives you
• some milk.
• FASCISM You have 2 cows. The
  State takes both and sells you
• some milk.
• NAZISM You have 2 cows. The
  State takes both and shoots you.
• BUREAUCRATISM You have 2 cows. The State takes
  both, shoots one, milks the other, and then
  throws the milk away...
• TRADITIONAL CAPITALISM You have two cows. You
  sell one
• and buy a bull. Your herd multiplies, and
  the
• economy grows. You sell them and retire on
  the income.
• ???? University of Westminster

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• AN AMERICAN CORPORATION You have two
  cows. You sell one, and force the
  other to produce the milk of four
  cows. Later, you hire a consultant to
  analyse why the cow has dropped dead.
  
• A FRENCH CORPORATION You have two
  cows. You go on strike, organise a
  riot, and block the roads, because you
  want three cows.
• A GERMAN CORPORATION You have two
  cows. You re-engineer them so they
  live for 100 years, eat once a month,
  and milk themselves.
• AN ITALIAN CORPORATION You have two
  cows, but you don't know where they are.
  You decide to have lunch.
• A RUSSIAN CORPORATION You have two
  cows. You count them and learn you
  have five cows. You count them again
  and learn you have 42 cows. You count
  them again and learn you have 2 cows.
  You stop counting cows and open another bottle of
  vodka.
• ???? University of Westminster

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??a µ??t??? (? ?p?de??µa) e??a?

• .ap??p???µ??? e????a t?? p?a?µat???t?ta?.
  ?µpe????e? ? p??pe? ?a eµpe????e? ta sp??da??te?a
  t??????st?? st???e?a p?? ?e?????ta? ???s?µa ??a
  ?a apa?t????? s???e???µ??a e??t?µata. ????
• ? afa??es? ?e? p??pe? ?a e??a? a??a??et? ?
  afa??es? ap? t?? p?a?µat???t?ta ?a? t?? ap??a?t?
  a???µ? st???e??? t??.

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???t??a ???s?µ?p?????ta?

• se ??e? s?ed?? t?? ?????????? ep?st?µe?. ?.?.
  a?afe??µaste se µ??t??a ?ap?ta??sµ?? ?p??
  ????ste ?a? se ??µµat??? µ??t??a ? ??????µ???
  µ??t??a.
• Se p????? pe??pt?se?? ta µ??t??a st?? ??????????
  ep?st?µe? de? ?e???????? ap? t??? ?de?t?p???
  (Idealtypen) t?? Max Weber.
• ?d?a?te?a st?? ??????µ??? ? ?atas?e?? µ??t????
  s???st? d?aded?µ??? p?a?t??? p?? a???p??e? t??
  d??at?t?te? t?? µa??µat????.

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?e?t???? st???e?a e??? ??????µ???? µ??t????

• ?a?ad????-s?????e?(assumptions,premises)??a
  ?esµ??? ??p p?? ?aµß????ta? ?? a???e??, a??? de?
  ap?de??????ta? (? d?at?p?s? e??a? t?te a?
  de????µe ?t?),
• ???sµ?? t?? µetaß??t??,
• Sta?e??? ? pa??µet??? st? µ??t???,
• ????e?e?? µetaß??t?? (s???? µetaß??t?? ?????ta?
  e???e?e?? µe t? ß???e?a t?? ??t?a? ceteris
  paribus),
• ??d??e?e?? µetaß??t??, ?? µetaß???? t?? ?p????
  ?????? d?e?e????ta?,
• ?µpe?????? s??se?? µeta?? t?? µetaß??t??
  (??µ???, ?p???se??) s?????? µe t? µ??f?
  s??a?t?se??. ?? eµpe?????? s??se?? e??a? ta
  ap?te??sµata p?? pa?????ta? ap? ta µ??t??a.

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??a t?p??? pa??de??µa ??????µ???? µ??t????

• .??af??eta? st? ??t?s?. Se a?t?
• ? pa?ad???-s?????? e??a? ? ??????????
  s?µpe??f???,
• ?? µetaß??t?? e??a? ? t?µ? (p1) ?a? ? ??t??µe??
  p?s?t?ta (q1),
• ? eµpe????? s??s? d??eta? µe t? s????t?s?
• p1 f ( q1) ?p?? dq1/dp1gt 0

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???? ??a ?a f??s??µe se a?t? ???s?µ?p????µe.

• ..?? ??t?a ceteris paribus.
• ???ad? de??µaste ?t? se µ?a pe???d? t? e?s?d?µa
  ?a? ???a µe???? (? d?µ? t?? p??t?µ?se?? t??
  ?ata?a??t?, ?? t?µ?? ????? p?????t??, ?a? t?
  e?s?d?µ? t??) µ????? aµet?ß??ta!
• ? ??µ?? t?? ??t?s?? s????eta? ap? ??a e???te??
  µ??t??? p?? pe???aµß??e? ?a? ?esµ???? pa?ad????
  (p.?. de? ?p???e? ??a? µ??? ?ata?a??t?? ??p) ?a?
  t? e?s?d?µ? t??.

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?? µ??t??? µa?

• ???a? e? t??e? µ?a ?p??et??? ?atas?e??.
• ?e???e? p??, ?p? ???sµ??e? s?????e?, ?a
  a?t?d??s??? ?ata?a??t?? ?a? pa?a????? a? a????e?
  ? µe???e? ? t?µ? t?? p?????t??.
• ?ata?????µe se a?t? de??µe??? ep?s?? ?t? ?????
  pa?????te? p?? st?? p?a?µat???t?ta pa????? ????
  µ????? sta?e??? (ceteris paribus).
• ?d? t? µ??t??? µp??e? ?a ???s?µ?p????e? ??a ?a
  a?a?????? p?a?t??? p??ß??µata.

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Ge???? ?a? ap? t?p??? ?p???

• ???e µ??t??? ap?te?e?ta? ap? pa?ad???? ?a?
  s?µpe??sµata. ?e???e? ?t? ?p? ???sµ??e?
  p???p???se?? p????pt??? ?????? (pa?????ta?)
  ???sµ??a ap?te??sµata.
• ??a ap?t??esµa p?? pa??????e µe t?? t??p? a?t?
  de? µp??e? ?a e??a? ?????, e?t?? e?? ? e?e???t??
  ?p?p?se? se ???? st?? pa?a???? t?? ap? t??
  pa?ad????.
• ???a? ?????? a?????, p????pte? ap? t??
  pa?ad???? (a? p????pte?).
• ? t?p??? d?at?p?s? e??a? a? de??? a?t? ?a?
  e?e???, t?te p????pte? ?t?.

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• ????S