general secondary education. Only after 9 years of schooling would a decision about what type of upper secondary education – academic or vocational – be undertaken. In other words, the new system postponed the choice of type of curriculum at the secondary level (general or vocational) for one year. This structural change was accompanied by curricular reform. A concept of core curricula was developed which aimed to provide schools with extensive scope of autonomy and responsibility. A system of examination and tests at the end of primary and lower secondary were introduced.

We use the variation created by the policy change in 1999 to test the impact on test scores over time. Specifically, we estimate a difference in difference model that compares the change in test scores of the likely vocational school students that were able to study in the general, academic track because of the change in school policy. The purpose of our paper is to explain the significant improvement in international achievement tests by Poland in recent years. We find that, on average, that the reform was associated with significant improvements.

In math, Poland improved its score by 0.25 of a standard deviation. In reading the increase is 0.28 of a standard deviation. In science, the scores increased by 0.16 of a standard deviation. We confirm these results using our evaluation model – propensity score matching and differences in differences to create counterfactual scores for the group of likely vocational students in subsequent years – and the OECD’s Program for International Student Assessment (PISA), an internationally comparable standardized student test conducted every three years to test reading, mathematics and science achievement of 15-year-olds, data for 2000, 2003 and 2006, using 2000 as the baseline since most of the existing students were continuing their lower secondary schooling under the old system. We explore threats to identification using among other things decomposition analysis We conclude that the reform is associated with an improvement in likely vocational students’ scores of about 100 points, or a whole standard deviation. We explore the implications using as well a 2006 special application of PISA in Poland to 16 and 17 year-olds, and warn of the dangers of early vocationalization.

The organization of the paper is as follows. Section 2 describes the policy change in Poland. Section 3 describes the increase in test scores over time. Our hypotheses are presented in Section 4. Section 5 describes our empirical methods and data. Section 6 presents the average impact results. Additional analyses are presented in section 7. Finally, we summarize our conclusions and discuss the implications in section 8.

# **2. Reform of 1998-1999**

In 1998, the Minister of Education presented the outline of the reform. The following goals were set (Ministry of National Education 1998):

1. Raising the level of education in society by increasing the number of people with secondary and higher education qualifications;

2. Ensuring equal educational opportunities; and 3. Supporting improvements in the quality of education.

The reform was envisaged to cover the following areas: 3