subsidies equal to the per-pupil financing granted<sup>to publicschools.The enrollmentshare</sup> of independent schools increased from 1 percent in<sup>1991to 4 percentin 2002. Parents</sup> with children in independent schools appear to be better<sup>educatedthan those in public</sup> schools, and they seem to be making their choices to avoid<sup>schools with large sharesof</sup> non-Nordic immigrants (Daun 2003). A study in<sup>one largemunicipality foundthat some</sup> schools with large declines in enrollment were unable<sup>to attractbetter teachers,but that</sup> others were able to establish new market profiles (Daun<sup>2003).</sup> Evidence on systematic bias in the estimate of<sup>effort ismixed in England, and</sup> evidence on the outcomes of the voucher program is unclear.<sup>A seriesof laws beginning</sup> in 1980 created a quasi-market in government-financed<sup>basic education England</sup> (LeGrand 1991, Walford 1997, Walford 2003).<sup>The1988EducationReform Act</sup> transferred control of budgets and personnel hiring<sup>to state-maintained schools,linked</sup> school funding to age-weighted enrollment figures, allowed<sup>parents to attend anyschool</sup> with available spaces, and required schools to follow the<sup>National Curriculum.In 1993</sup> schools were allowed to select 10 percent of their<sup>students on the basis of musicalor</sup> other abilities, and other legislation that same year<sup>permitted existing privateschoolsor</sup> independent sponsors to establish grant-maintained<sup>schools.Seven new schools were</sup> formed from 1993-1997, and seven more have<sup>been established under the Labor</sup> Government, which has retained the voucher-like<sup>systemin English education.</sup> A series of case studies has argued that the choice system<sup>has led to increased</sup> social segregation among schools, as students<sup>sorted based partly on the social mix in</sup> schools and as schools started to select students<sup>(Ball and Vincent1998,Gewirtz,Ball,</sup> and Bowe 1995), but statistical analyses of class<sup>segregationhave been inconclusive</sup> (Gorard and Fitz 2000, Gibson and Asthana 2000,<sup>Levacicand Woods1999), partly</sup> because the previous system in which students<sup>were assignedto schools basedon</sup> residence, "selection by mortgage," had already<sup>created substantial sorting. Achievement</sup> scores of students in the system increased during<sup>the1990s,and somestudiesargue that</sup> competition among schools, as measured by private<sup>sectorenrollmentshare, number of</sup> schools, or a Herfindahl index, is associated<sup>with higher test scores.(Bradleyand Taylor</sup> 2002, Millington and Bradley 1998), but other<sup>studiesfind mixed results.One, in</sup> particular, used interviews with headmasters to try to<sup>establisha link betweenstructural</sup> competition in a market, measured by the number<sup>of firms or a Herfindahlindex,and</sup> competitive behavior, and found that the relationship<sup>is looser than believed,being</sup> mitigated by amount of space available, product<sup>differentiation(type of education</sup> offered), and other factors. It also found that<sup>theimpact of competitionin performanceis</sup> sensitive to the measure of competition used (Levacic<sup>2001).Alongside the voucher</sup> system, the Conservative government in the early<sup>1990s introducednationwidetesting,</sup> required publication of test results, and school<sup>inspections -a system of "namingand</sup> 12