How the following events can affect the natural rate of unemployment (increase, decrease or leave unchanged)? Give brief explanations for each answer. (i) an increase in the size of unemployment benefits ii) a decrease in the competitiveness of domestic goods in the world markets iii) a strengthening of the trade unions' market power (iv) technological progress (v) an increase in the number of women in the labour market (vi) a prolonged severe recession in the key industries of the economy (vii) a recession in the countries-main trading partners (ViII a rise in taxes paid by firms for each worker (ix) reducing barriers to the workers' mobility (x) an increase in the number of discouraged workers (xi) an improvement of the system of information about the existing vacancies (xii) a decrease in labour productivity (xiii) an increase in the number of government retraining programs (xiv) an increase in the educational level of the labour force (xv) an increase in the number of low-skilled workers in the labour market