Professor Erling Eide: Forelesninger i rettsøkonomi (B og M) 1 Emne og problemstillinger 1.1 Hva er rettsøkonomi 1.1.1 Rettsøkonomiske hovedspørsmål Hvordan virker rettsreglene? Teori om individuell rasjonell adferd Rettsregler som insentiver Teori om samhandling, markedsteori Effektiv ressursutnyttelse? Hva slags rettsregler bør vi ha? Velferdsteori (liberal) Velferdsteoriens fundamentalteorem Pareto-effektivitet Kaldor-Hicks-effektivitet Hvorfor har vi fått de rettsregler vi har? Effektivitetsteorien Interessegruppeteorien 1.1.2 Rettsøkonomi og reelle hensyn Viktig for alle tre hovedspørsmål ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

1.2 Kort historikk 1.3 Rettens virkninger 1.3.1 Rasjonell adferd US ”Law Schools” sentrale Nobelprisvinnere: Coase, Becker, Buchanan, Nash Cooter and Ulen: Preface: Alle jus-studenter lærer noe RØ RØ er er blitt en viktig ”organizing philosohy in US legal education” Europa: Nølende, men masterstudier 1.3 Rettens virkninger Krav om å utrede virkninger i rettspolitikk og rettsanvendelse Utredningsinstruksen, Kgl. res. 24. juni 2005 1.3.1 Rasjonell adferd Formålsrasjonelle aktører tilpasser seg rettsregler som best de kan Ikke spesielt økonomisk at retten skaper insentiver Egeninteresse forskjellig fra egoisme ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

1.3.2 Normavhengig og formålsstyrt adferd 1.3.3 Rettsregler som incentiver Regler som betjener private parter Frikonkurranseforutsetninger Regler som tar sikte på å fremme politiske målsetninger Skatterett Sanksjoner Uventede konsekvenser av rasjonell tilpasning til regler ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

1.4 Vurderinger av retten (av dens virkninger) 1.4.1 Velferdsteori og velferdskriterier Avveining av fordeler og ulemper ved en regel eller avgjørelse krever et kriterium Effektivtetskriterier 1.4.2 Velferdsteoriens fundamentalteorem: (1) Enhver likevektsløsning i frikonkurransemodellen er Pareto-effektiv (2) Hvis inntakt kan omfordeles kostnadsfritt, kan en hvilken som helst Pareto-effektiv løsning oppnås ved frikonkurranse. FK-løsningen innebærer tre partielle effektivitetsforhold: Produksjonseffektivitet Konsumeffektivitet Allokeringseffektivitet ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

1.4.3 Pareto-effektivitet To individer, X og Y, hvis nytte (evnt inntekt) måles langs aksene P: Selvberging Q, R, …: Resultater av samarbeid, spesialisering etc. R er Pareto-preferert fremfor P Q er Pareto-preferert fremfor P Alle punkt i området PCD er Pareto-preferert fremfor P Q er et Pareto-effektivt punkt Alle punkt på kurven CD er Pareto-effektive Individ Xs inntekt Individ Ys innt. D R C Xs inntekt av alt. P Ys inn-tekt av alt. P Q P ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

1.4.3 Pareto-effektivitet S To individer, X og Y, hvis nytte (evnt inntekt) måles langs aksene P: Selvberging Q, R, …: Resultater av samarbeid, spesialisering etc. R er Pareto-preferert fremfor P Q er Pareto-preferert fremfor P Alle punkt i området PCD er Pareto-preferert fremfor P Q er et Pareto-effektivt punkt Alle punkt på kurven CD er Pareto-effektive Individ Xs inntekt Individ Ys innt. D R C Xs inntekt av alt. P Ys inn-tekt av alt. P Q P ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ S m:\md\u\VALRETØK\PP-Disp

1.4.4 Kaldor-Hicks-effektivitet Pareto-kriteriet er ofte utilstrekkelig Kaldor-Hicks-kriteriet: En rettsregel (prosjekt e.l.) er ønskelig hvis den skaper store nok verdier på vinnernes hender til at taperne kan kompenseres. Benyttes ved sammenligning av to alternativ, A og B. B kalles Kaldor-Hicks-effektivt (eller også potensielt Pareto-preferert) hvis kriteriet er oppfylt. Kritikk av KH-kriteriet ”Unfair” (=urimelig?) Noen taper, idet kompensasjon ofte ikke gis KH-kriteriet passer best der hovedpoenget er størst mulig ”kake” (kontraktsrett?) KH-kriteriet forutsetter målbarhet Ikke kriteriets ”skyld”-- Verden er vrien Kriteriet klargjør avveiningsproblemer 1.4.5 Effektivitet og rettferdighet Motsetninger eller sammenfall ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

2 ANALYSEVERKTØY OG METODER 2.1 Modellbruk i RØ Modeller inneholder: Tekniske relasjoner (eks: produktmengdens funksjon av årsverk) Adferdsrelasjoner (eks: etterspørselens funksjon av pris) Likevektsbetingelser (eks: tilbud lik etterspørsel) Modell = teori = forenkling ”Alle” benytter modeller Jurister i rettspolitikk og i analyse av reelle hensyn ved rettsanv. 2.2 Frikonkurransemodellen 2.1.1 Hvorfor (den urealistiske?) FK-modellen? Tilnærmet riktig Oppskrift på organisering av samfunnet Enkel, gir klare (og ønskelige?) konklusjoner Alternative modeller mangelvare ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

2.1.2 Ønskelig produksjon Mengde Marginal betalingsvillighet Marginale alternativ-kostnader MBV MAK M Alternativkostnad: Verdi av produksjonsfaktorer i beste alternativ anvendelse MAK: Verdi av produksjonsfaktorer nødvendig for å produsere én enhet til Betalingsvillighet: Maksimal verdsettelse (betalingsvillighet) for et gode MBV: Betalingsvillighet for én enhet til Effektiv (samfunnsøkonomisk ønskelig) produksjon: M ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

2.2.3 FK-løsningen er Pareto-effektiv (Velferdsteorien) 2.2.2 Hvordan oppnå M? Innfør FK! Tilbudskurven viser hvor mye tilbyderne (produsentene) ønsker å tilby til alternative priser Etterspørselskurven viser hvor mye etterspørrerne samlet ønsker til gitte priser T-kurven sammenfaller med MAK-kurven E-kurven sammenfaller med MBV-kurven M er likevektsløsningen: aktørene vil ikke ønske et annet resultat DVS: FK-løsningen realiserer den effektive løsning 2.2.3 FK-løsningen er Pareto-effektiv (Velferdsteorien) 2.2.4 Samfunnsøkonomisk overskudd Produsentoverskudd Konsumentoverskudd 2.2.4 Sviktende forutsetninger for FK-modellen Færre aktører (monopol etc.) Eksterne virkninger mv (ikke full internalisering) Transaksjonskostnader ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

2.3 Transaksjonskostnader Søkekostnader Forhandlingskostnader Kontrollkostnader Informasjonskostnader inngår i alle de ovennevnte TK forhindrer avtaler som parter i og for seg ønsker inngått Privatretten reduserer TK 2.4 Partielle analyser 2.5 TK, partielle analyser og effektivitet 2.6 Lovgiver-, administrasjons- og domstolkostn. 2.7 Kort og lang sikt _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________________________________________ m:\md\u\VALRETØK\PP-Disp

2.8 Valg under usikkerhet Forventet verdi av usikkert prosjekt Mulige resultater: X1, X2, … Xn Sannsynligheter: P1, P2, … Pn Forventet verdi: E[X] = P1X1 + P2X2+ … + PnXn Holdning til risiko: Risikonøytralitet: Prosjekt 1 og 2 like gode Risikoaversjon: Prosjekt 1 bedre enn prosjekt 2 Sikkerhetsekvivalent: Det beløp som vil gjøre prosjekt 2 like godt som prosjekt 1

2.9 Forsikring 2.9.1 Eksempel: Forutsetninger: Verdi av gjenstand som kan forsikres: 1 000 Kjent sannsynlighet for at gjenstanden blir ødelagt: 0,02 Forventet skade : 0,02∙1000 = 20 Forsikringsselskapets administrasjonskostnader: 3 Forsikringsselskapets krav til fortjeneste: 1 Et forsikringsselskap (som kan antas å være risikonøytralt) vil tilby forsikring til en premie på (minst) 20 + 4 = 24 Risikonøytral eier Usikkert alternativ (ikke forsikring): 0,98∙1000 + 0,02 ∙0 = 980 Sikkert alternativ (forsikring): 1000 – 24 = 976 ønsker å forsikre hvis forsikringspremien er lavere enn 20 Risikouvillig eier ønsker forsikring hvis sikkerhetsekvivalenten er høyere enn 980 – 976 = 4

2.9 Forsikring (forts) 2.9.2 Adferdsrisiko (”moral hazard”) Forsikring gir incentiv til redusert forsiktighet/påpasselighet (som forsikringsselskapet ikke/vanskelig kan observere) Konsekvens (løsning?): egenandeler 2.9.3 Ugunstig utvelgelse Forsikringspremien avspeiler resultatet av forsikringstagernes gjennomsnittlige forsiktighet/påpasselighet. Særlig forsiktige forsikringstagere vil finne forsikringspremien for høy og unnlate å forsikre. Forsikringspremiene vil måtte forhøyes, etc.

2.10 SPILLTEORI DEFINISJONER: Fangens dilemma Spillere: Aktører som fatter beslutninger (bestemmer handlinger) Handling: Spillernes valg Utfall: Den nytte en spiller oppnår avhengig av egne og andres handlinger Informasjon: Spillernes kunnskaper om mulige handlinger og mulige utfall Strategi: Handlingsregel for flere trekk i et spill (= handling ved bare ett trekk) Resultat: De verdier av spillets elementer forskeren finner interessante når spillet er slutt Beste respons: Den strategi som gir det beste utfall i en gitt situasjon (gitt den annens strategi) Dominerende strategi: Strategi som er den beste respons på enhver strategi andre måtte velge Forutsetning: Rasjonelle spillere: Målsetning størst mulig nytte (her lik inntekt) Løsningsbegreper (likevektsbegreper): Avklarer spillernes beste strategier Dominerende strategilikevekt Iterativ dominerende strategilikevekt Nash-likevekt Fangens dilemma ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ KOLONNE SAMARBEIDER IKKE (ANGIR) -1 , -1 -6 , 0 LINJE 0 , -6 -5 , -5 m:\md\u\VALRETØK\PP-Disp