Endogenous Technological Change under Uncertainty

How does risk or uncertainty in the productivity of research affect the growth rate of the economy? To answer this question, a model of endogenous technological change is used where sustained growth stems from intentional investments in R&D from profit-maximizing firms. The uncertainty arises from the productivity of these investments in R&D. The main result of this analysis is that the relationship between long-run growth and uncertainty (on the productivity of knowledge creation) depends on two main factors - the returns to scale in knowledge creation (increasing or non-increasing) and the value of the elasticity of intertemporal substitution (higher or lower than some critical value). Based on empirical studies on the returns to scale in knowledge creation (”non-increasing”) and the value of the elasticity of intertemporal substitution (”higher than the critical value”), we expect a negative relationship between long-run growth and uncertainty regarding the productivity of knowledge creation.Long-run growth, Technological change, Uncertainty

On Growth and Fluctuations: The Option to Adobt New Technology

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On Taxation in a Two-Sector Endogenous Growth Model with Endogenous Labor Supply

This paper studies the effects of taxation on long-run growth in a two-sector endogenous growth model with (i) physical capital as an input in the education sector and (ii) leisure as an additional argument in the utility function. Due to the flexibility of labor supply, taxation of income may induce agents to spend more or less time on leisure activities. Income taxation - the same rate applies for capital and labor income - reduces the growth rate. The contribution of endogenous leisure in this case is confined to reducing or increasing the size of the effect on the growth rate. The same is true if only labor income is taxed. However, if only capital income is taxed, the sign of the effect may reverse. In that case, the positive effect of the increase in total non-leisure time dominates the direct negative effect, implying that capital taxation increases the long-run growth rate.

Are older workers overpaid? A literature review

It is widely believed that wage and productivity profiles of individual workers do not coincide at all ages. We give an overview of the theories which provide a rationale for this, and discuss the empirical literature. Human capital theories typically imply that wages rise with tenure, so that job reallocation at old age would imply a wage cut. Incentive theories typically imply that wages exceed productivity at the end of a worker's career. Bargaining power of unions may also lead to 'overpayment' of older workers. Some general conclusions regarding the wages of older workers are formulated on the basis of the authors' reading of the empirical literature.

Analyzing labour supply of elderly people: a life-cycle approach

In light of the ageing of the Dutch society, policy measures aim at increasing the participation rate of elderly workers, particularly in the age-group between 55 and 64. This paper develops a stylized numerical simulation model. This model describes consumption, savings and labour supply behaviour over the life cycle to analyze the labour-market implications of such proposals. For example, we simulate a shift in the (normal) retirement age from 65 to 67, the elimination of the Social Security premium exemption after age 65, and a premium on first-tier pension benefits if the commencement date of these benefits is postponed. Each of these reforms affect the economic outcomes via wealth effects, income effects and inter- and intratemporal substitution effects. The stylized model offers a profound theoretical underpinning which helps us to understand these policy effects over the entire life cycle of individuals. However, the numerical outcomes should be taken with some caution as the model ignores insights of behavioural economics (such as ‘framing effects’).

Endogenous Technological Change under Uncertainty

How does risk or uncertainty in the productivity of research affect the growth rate of the economy? To answer this question, a model of endogenous technological change is used where sustained growth stems from intentional investments in R&D from profit-maximizing firms. The uncertainty arises from the productivity of these investments in R&D. The main result of this analysis is that the relationship between long-run growth and uncertainty (on the productivity of knowledge creation) depends on two main factors - the returns to scale in knowledge creation (increasing or non-increasing) and the value of the elasticity of intertemporal substitution (higher or lower than some critical value).Based on empirical studies on the returns to scale in knowledge creation ("non-increasing") and the value of the elasticity of intertemporal substitution ("higher than the critical value"), we expect a negative relationship between long-run growth and uncertainty regarding the productivity of knowledge creation

Uncertain Technological Change under Capital Mobility

The analysis in this paper shows that unpredictable variations in economic productivity may have a positive or negative effect on the average growth rate of output. This theoretical ambiguity result is not solely determined by the value of the elasticity of intertemporal substitution (of consumption) - as is the case in earlier analyses - but depends on two factors. That is, the growth-uncertainty relationship depends on whether returns to scale in knowledge creation are increasing or non-increasing and whether the elasticity of intertemporal substitution (of profits) is higher or lower than some critical value. Empirical studies concerning these two factors indicate that unpredictable variations in economic productivity have a negative effect on the average long-run growth rate

On Taxation in a Two-Sector Endogenous Growth Model with Endogenous Labor Supply

This paper examines the effects of taxation on long-run growth in a two-sector endogenous growth model with (i) physical capital as an input in the education sector and (ii) leisure as an additional argument in the utility function. The analysis of the effects of taxation - including income taxation, capital income taxation and labor income taxation - distinguishes between the case with a unique (interior) balanced growth path and the case with multiple balanced growth paths. Due to the flexibility of labor supply, taxation of income may induce agents to spend more or less time on leisure activities. In the case of income taxation, where capital and labor income are taxed equally, the resulting effect on the growth rate is negative. The contribution of endogenous leisure is confined to reducing or increasing the size of the effect on the growth rate. If only capital income is taxed, the direction of the effect may reverse. In that case, the positive effect of the increase in total non-leisure time dominates the direct negative effect, implying that capital taxation increases the long-run growth rate

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe