Selasa, 10 Januari 2012

How better nutrition raised output per capita

Table 2.4 shows secular trends in the daily caloric supply in France and Great Britain from 1700 to 1989. Per capita availability of calories more than doubled in this period in France, and increased by about 50% in Great Britain, where caloric supply was 30% larger than that in France at the beginning of the period.
How did the substantial increase in calories per capita affect labor productivity? Labor productivity can be defined as the output of marketable goods and services that a typical worker can produce over the span of one day. Daily output per worker, in turn, can be decomposed into the output per calorie expended at work and the daily amount of calories expended on the job by a typical worker. By multiplying the daily output per worker by the number of workers per inhabitant (which is called the labor force participation rate) output per worker is transformed into output per capita, which is used as a measure of the standard of living: Output of goods and services produced per capita per day daily output of goods and services per calorie expended in their production daily amount of calories expended in production per worker labor force participation rate In this decomposition, the technological breakthroughs in farming raised yields for a given effort level, represented here as increases in the output per calorie expended in production. At given levels of annual calories expended in production per worker and labor force participation rate, this must have raised the volume of agricultural output per capita. Higher levels of labor productivity in agriculture also allowed parts of the labor force to be employed in nonagricultural sectors of the economy without reducing farm output per person, thus diversifying the range of goods and services produced domestically. To understand the full effect of gains in agricultural efficiency, however, it is necessary to take into account how the additional calories were used. Those adults who had been working before the development and diffusion of more productive farming methods could now increase the annual amount of calories expended while working, either by performing more energy-intensive tasks or by working additional hours, or both. This increase in calories expended in production by a typical worker further increased the amount of calories produced (and ultimately consumed) per capita. In addition to boosting the calories available to workers, the expansion of the food supply also made more calories available for members of the poorest segment of the adult population who had had only enough energy above maintenance for a few hours of strolling each day – about the amount needed by a beggar – but less on average than that needed for just one hour of the heavy manual labor required in agriculture. To the extent that these persons now had the energy to work, they raised the labor force participation rate, which led to a further increase in per capita output. Table 2.5 summarizes the daily amount of energy available for work in France, and England and Wales from 1700 to 1980. The most impressive gains are reected by the data for France, where calories available for work increased nearly fivefold within less than 200 years. In total, by increasing agricultural yields per calorie expended, the Second Agricultural Revolution expanded the availability of calories per capita, drawing more people into the labor force and raising on-the-job calorie expenditures of those working. This boost in the population’s productive capacity in turn fueled further growth not only in food output per capita. It also helped to raise the output in all other, nonagricultural sectors of the economy that benefited from an increase in workers and hours worked.
The effect of improved nutrition on productivity and output
Table 2.5
A comparison of energy available for work daily per consuming unit in France, and England and Wales, 1700–1980 (in kcal)
Year France England and Wales
1700                                                                                                       720
1705 439
1750                                                                                                       812
1785 600
1800                                                                                                       858  
1850                                                                                                       1014
1870 1671
1975 2136
1980                                                                                                       1793
Source: Fogel et al. (in press).

Empirical estimate
Time series of anthropometric and macroeconomic statistics can be combined to estimate the contribution of better nutrition to the growth of output per person. The most reliable and complete data in this regard have been collected for England. As noted in the introduction, between 1780 and 1979 British per capita income grew at an annual rate of about 1.15% (Maddison, 1982). Data are now available to measure the changes in calories available for work and the labor force participation rate. For Britain, it has been estimated that the increases in the supply of calories lifted as much as one fifth of all consuming units above the threshold required for work. As a result, the labor force participation rate increased by 25% over 200 years, contributing 0.11% to the annual British growth rate between 1780 and 1980 (1.25 1 0.0011). 0.005 The increased supply of calories also raised the average consumption of calories by those in the labor force from 2944 kcal per consuming unit in c.1790 to 3701kcal per consuming unit in 1980. Of these amounts, 1009 kcal were available for work inc. 1790 and 1569 in 1980, so that calories available for discretionary activities increased by about 56% during the two centuries. If it is assumed that the proportion of the avail-able energy devoted to work has been unchanged between the end points of the period, then the increase in the amount of energy available for work contributed about 0.23% per annum to the annual growth rate of per capita income (1.561 0.0023).0.0053 Thus, in combination, bringing the ultra-poor into the labor force and raising the energy available for work by those in the labor force, explains about 30% of British growth in per capita income over the past two centuries [(0.0023 0.0011) 0.0115 0.30]. As incomes in OECD countries have risen, the share of discretionary time devoted to working for income has declined. Consequently, it is unlikely that further increases in the amount of calories available per person in those countries will raise labor force. However, the immediate effect of better nutrition on labor productivity still holds enormous potential in poor countries where malnutrition is widespread.
The self-reinforcing cycle of greater body size and higher productivity
In addition to the direct effect of better nutrition on the growth of output per person, the conquest of chronic malnutrition has had a long-term effect on human physiology, which has taken several generations to unfold. The role of long-term changes of nutritional status in altering body size is inferred from applying energy cost accounting to an analysis of food balance sheets. In particular, to have the energy necessary to produce the national product of either France or England c. 1700, the typical adult male must have been quite short and very light in weight. The smaller body size reduced the basal metabolic rate and thereby freed up calories that could be used for work. As per capita food supplies expanded, so did not only hours worked but also body size. The increase in body size, in turn, improved health and the capacity of individuals to raise labor productivity further, thus rein-forcing the initial increase in labor productivity.


Komentar ini telah dihapus oleh pengarang.

Posting Komentar