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In a nutshell: The economics of progress

In the picture above, there are no people to be seen. But there are some nonetheless. One person runs the harvester that is transporting the grain (already freed from the ears) onto a tractor-trailer where a second person sits at the wheel. That's it. No more people are needed nowadays to bring in the harvest.

I took this photograph while hiking through my home region Taubertal in the south of Germany, last weekend.

When I walked across the fields, I imagined how many people would be working there a hundred years ago. These fields must have been crowded places back then. 

In many countries schools’ summer holidays are still strangely long (in Germany it's six weeks). It is because, in former times, the majority had to help with the harvest. For example, wheat had to be cut and bundled into sheaves, stacked upright. After that, the edible part of the grain had to be loosened from the straw by threshing (before threshing was mechanized, about one-quarter of agricultural labour was devoted to it). And later, the wheat had to be separated from the chaff (done by repeatedly tossing the grain up into a light wind which gradually blew the lighter chaff away). 

In the last three decades alone, worldwide employment in agriculture decreased from 44 to 27% (% of total employment). That is just average. The range is extremely wide. In Burundi, 86% of all the labour force is working in agriculture; it is 2% in Canada. 

In rich countries, only a single-digit percentage of total employment is working in the agricultural sector. Opposite to the decrease of the percentage, the agriculture value per worker increased. "This is likely to result from several factors including technology adoption, affordability of agricultural inputs, and the implementation of more productive practices," Max Roser wrote at Our World in Data

In Germany, only 1,3% of all employees are employed in the agriculture sector. This small portion is significant enough to feed everyone. Statistically speaking, in 1960, one farmer in Germany fed 17 people, whereas today the number has risen to 134.

The progress in agriculture set off millions of workers. They lost their jobs and living; they had to find new ones. And most of them did. We couldn't live this life we are living today if everything had stayed the same. If progress had been prevented, almost everybody would still harvest in the summer. - Seen that way, I like the picture above where no one is to be seen.   

Notes 

https://en.wikipedia.org/wiki/Threshing

https://en.wikipedia.org/wiki/Chaff

https://data.worldbank.org/indicator/SL.AGR.EMPL.ZS

https://ourworldindata.org/grapher/number-of-people-employed-in-agriculture-since-1800

https://ourworldindata.org/grapher/agriculture-value-added-per-worker-vs-gdp-per-capita

https://www.bmel-statistik.de/landwirtschaft/testbetriebsnetz/testbetriebsnetz-landwirtschaft-buchfuehrungsergebnisse/ (German)

https://www.bpb.de/gesellschaft/umwelt/landwirtschaft/325872/strukturwandel#footnode5-5 (German)