such as training, adoption of new technology and use of quality control methods. While improvements in these intermediate outcomes were supposed to translate into improved performance, the authors did not find statistically significant net gains in wages, export orientation or productivity. The authors concluded that greater attention to differential treatment “doses”—for example, more versus less training or type of consulting services provided—larger sample sizes, and tracking beneficiaries over a longer horizon may be needed to determine whether these interventions have the hypothesized positive performance impacts.

# _Evaluations in progress_

With respect to Fondo PYME, in 2009 a team from the Instituto Tecnológico de Monterrey (Mexico City campus) carried out the first evaluation that included aspects of design, processes, perceptions and impacts (ITESM-CCM 2009). The evaluation assessed the fund’s capacity to create and maintain formal firms and formal jobs, as well as its potential to increase productivity and sales for established firms, using a methodology based on data envelopment analysis. The study found positive impacts on the productivity of beneficiary firms of about 4 percent on average one year after treatment with respect to non-beneficiary control firms. Business incubators, business accelerators, supplier development, productive projects and seed capital were the support mechanisms with greater impact on productivity, in some case with more than 10 percent. Fondo PYME also showed positive impacts on sales of about US$19,000 in the year following treatment. The evaluation should be taken with reservation because of possible biases due to self-selection and unobserved firm heterogeneity that could have contributed to the positive results. As shown in Section 4, these biases could lead to over-estimating the impact of SME programs.

# _Summing up_

There are wide variations in evaluation design and methodology, and few programs in Mexico have had impact evaluations, hindering the comparison of programs on the basis of their effectiveness and efficiency . Most of the evaluations have been quantitative, and in those cases with impact evaluations there had been some doubts about the quality of the control group and the methodology. The most rigorous impact evaluation is by Tan and Lopez (2005), but it was limited by small sample sizes and by the lack of more rounds of the panel in order to assess the effects of the interventions over a longer time span. The present analysis represents an improvement over the previous impact evaluation study in terms of the methodology and the information used. First, the present research uses a yearly panel over ten years, which provides more continuous information about entry and exit of firms. As well, a larger sample of firms participating in SME programs is available from the last round of the ENESTYC 2005 survey. Finally, a bounding methodology applied in the panel data allowed for testing the robustness of the impacts of programs to firm exit.

# **4.- DATA**

The paper uses the National Employment Salary, Training and Technology ( _Encuesta Nacional de Empleo, Salarios, Capacitación y Tecnología_ —ENESTYC) and Annual 16