Meat supply shares

[nk027]

So we use meat supply shares to calculate some other animal product supply shares.

This is done with a subset per year and per region, then we set shares = value / sum(value). Now there's likely cases where no value (i.e. production) is available - leading to NaN. Atm this is probably not a problem since we NAs and 0s are used interchangeably, but when switching to proper coding of NA values we have to watch out.

[nk027]

To add to this:

In this step we potentially overwrite available information and introduce quite some errors. Consider e.g. Armenia in 2005. Our meat-based shares are:

proc                     share_m
Cattle slaughtering      0.61
Buffaloes slaughtering   0.00
Sheep slaughtering       0.13
Goat slaughtering        0.00
Pigs slaughtering        0.16
Poultry slaughtering     0.08
Horses slaughtering      0.00

Once merged (a subset of) our data here looks as follows:

item                production  share  share_m
       Bovine Meat  34400       1.00   0.61
    Offals, Edible  10110              0.61
Fats, Animals, Raw   1975              0.61
   Hides and skins   5675       0.87   0.61
         Meat Meal      0              0.61
Mutton & Goat Meat     91       0.01   0.00
    Offals, Edible  10110              0.00
Fats, Animals, Raw   1975              0.00
   Hides and skins      0              0.00
         Meat Meal      0              0.00
           Pigmeat   9400              0.16
    Offals, Edible  10110              0.16
Fats, Animals, Raw   1975              0.16
         Meat Meal      0              0.16
              Eggs  29053              0.08
      Poultry Meat   4600              0.08
    Offals, Edible  10110              0.08
Fats, Animals, Raw   1975              0.08
         Meat Meal      0              0.08

Now as far as I can tell, we ignore the share variable and blindly apply share_m (as long as the processes match). This means we scale down Bovine Meat, Mutton & Goat Meat, Eggs, etc. according to the total split of meat production. This does not make sense. Furthermore, we ignore available information, such as the 0.87% share of Hides and skins stemming from one process or the Mutton & Goat Meat split.

[nk027]

So this may not be as problematic, since we subset to c("Offals, Edible", "Fats, Animals, Raw", "Meat Meal", "Hides and skins"). Still, we ignore available shares though (note that this seems to only be the case for Hides & Skins).

[nk027]

The supply shares for c("c120", "c121", "c122", "c123", "c124") are calculated based on c("c115", "c116", "c117", "c118", "c119"). The shares are recalculated over all items, even though they are available per input. See #38, might not make sense to have too much detail.