a: |
the lower-range or minimum value of a random variable |
A: |
an annual payment amount which, continued over n years, constitutes an annuity with a terminal value A_{n} = A[(1+i)^{n}-1]/i or which amortizes a PV where A = PV[i(1+i)^{n}]/[(1+i)^{n}-1] |
A_{n} |
a future amount to be received or paid in n years' time; it is equivalent to an annuity over n years of A = A_{n}i/[(1+i)^{n}-1] and has a PV of A_{n}/(1+i)^{n} |
AB: |
allocation budgeting |
ac: |
acre(s) |
ac ft: |
acre feet (of irrigation water) |
AME: |
adult male equivalent, a standardized unit of labour measurement |
APP: |
average physical product, equal to Y/X for Y = f(X) |
AU: |
animal unit, a standardized unit for aggregation or comparison of different types of animals |
AVP: |
average value product, equal to (APP)p_{y} |
b: |
the upper-range or maximum value of a random variable |
B: |
the resource pool available to the farmer or, in LP, the level of resource constraints or activities constituting the farm 'plan' at each iteration |
B: |
size of the available cash budget |
B/C: |
ratio of benefits to costs |
B-1: |
in AB and SP, the initial set of resource constraints |
B-i: |
in AB and SP, the balance of resource constraints after sequential introduction of the i-th activity into the plan, i = 1,2,... |
C: |
depending on context, cost or the coconut-to-copra conversion rate |
CDF: |
cumulative distribution function |
CE: |
a decision maker's certainty equivalent for a risky prospect |
cm: |
centimetre(s) |
COP: |
cost of production, calculated per unit of output as total cost divided by quantity of output, i.e., TC/Y |
CV: |
coefficient of variation, calculated as 100 _{} to express the standard deviation of a variable as a percentage of its mean |
CY: |
crop-cycle year of a perennial crop |
d: |
the constant annual rate of depreciation under the declining-balance method |
D: |
the annual depreciation cost as measured by the straight-line method |
D_{t}: |
the annual depreciation cost in year t as measured by the declining-balance or sum-of-integers methods |
DC: |
direct cost of an enterprise (or activity), calculated as the sum of its VC plus its share of farm FC |
DI: |
Simpson's diversity index, equal to _{} where S is the number of species or activities present; n_{i} is the number of individuals in the i-th species, or area devoted to the i-th species or activity, or income or value of the i-th species or activity; and N (=S n_{i}) is the total population of individuals across all species, or total area across all species or activities, or total farm income or value across all species or activities |
dU/dX: |
marginal utility of X for U = f(X) |
dY/dX: |
marginal product of X in Y = f(X) or the first derivative of Y with respect to X |
E: |
mean or expected value, calculated for a variable X as_{} for a sample of observations X_{1}, X_{2}.... X_{n} |
EMV: |
the expected money value of a risky prospect |
EU: |
subjective expected utility of a risky prospect |
EV: |
expected value of a risky prospect |
f_{0.i}: |
the i-th fractile of a probability distribution; a proportion 0.i of the distribution of a random variable X will lie below the value X = f_{0.i} |
FC: |
fixed cost |
F(PV): |
CDF of PV |
F(X): |
the cumulative probability or CDF of a random variable X |
G: |
yield of grain |
GAMS: |
General Algebraic Modelling System |
GM: |
gross margin, calculated as gross return less variable cost |
GR: |
gross return or gross revenue |
ha: |
hectare(s) |
HYV: |
high-yielding variety |
i: |
real annual rate of interest after correcting for inflation or deflation, equal to [(1+i*)/(1+w)]-1, or, when used as a subscript, denotes the i-th member of a set |
i*: |
nominal annual rate of interest or rate of discount |
IRR: |
internal rate of return defined as the annual interest rate i at which the PV of an investment's costs is equal to the PV of its gross returns |
K: |
in LP, the maximum level of an activity permitted by a particular constraint |
kg: |
kilogram(s) |
km: |
kilometre(s) |
L: |
the expected total years of useful life of a capital item |
LP: |
linear programming |
LU: |
labour unit, a standardized unit for measuring labour |
m: |
metre(s) |
m: |
the modal value of a random variable |
-M: |
in LP, the notional high negative p value placed on Q_{i} |
MC: |
marginal cost or the change in TC as one more unit of a variable input factor is used |
mds: |
maunds, a volumetric measure used in Pakistan and India |
MOTAD: |
Minimization of Total Absolute Deviations, a form of linear risk programming |
MPP: |
marginal physical product, equal to dY/dX for Y = f(X) |
mt: |
metric tonne(s) |
mths: |
months |
MVP: |
marginal value product, equal to (MPP)p_{y} |
n: |
depending on context, the number of observations on a variable, or the size of a sample, or the number of input factors in a production process, or the number of equal intervals (usually years) in a period of time |
n_{i}: |
for a given farm system, the number of individuals in the i-th species, or area devoted to the i-th species or activity, or income from the i-th species or activity; used in calculating the DI of a farm system |
N: |
depending on context, quantity of nitrogen fertilizer or, for a given farm system, the total population of individuals across all species, or total area across all species or activities, or total farm income or value across all species or activities; used in calculating the DI of a farm system |
no.: |
number |
NPK: |
fertilizer containing nitrogen, phosphorous and potassium |
NR: |
net return or net revenue, calculated as TGR minus TC |
Nu: |
Ngultrum; Bhutanese unit of currency |
OC: |
overhead costs, defined as fixed costs accrued on a whole-farm basis |
OGM: |
operational gross margin of an enterprise (or activity), calculated as TGR minus DC of the enterprise (or activity) |
O_{i}: |
the i-th possible outcome of a particular risky decision |
p: |
in LP, the unit price or value of each real or disposal activity; it is equivalent to an activity's unit GM |
p_{g}: |
unit price of grain |
p_{i}: |
unit price of the i-th good |
p_{n}: |
unit price of N |
p_{x}: |
unit price of input factor X |
p_{y}: |
unit price of product Y |
P: |
quantity of phosphate fertilizer |
pk: |
patok(s), a Javanese land unit equal to about 0.1 ha |
P(O_{i}): |
the decision maker's subjective probability for the occurrence of O_{i} |
P(R£ R*): |
the probability that net return R will be less than or equal to any nominated value R* |
PV: |
the present value of a future lump sum or stream of payments or of an item; if A_{n} is to be received n years from now, its PV is A_{n}/(1+i)^{n} assuming an annual interest rate of i |
PV_{t}: |
PV at time t |
P(X): |
probability of X |
q: |
number of times per year that compounding or discounting is to occur |
Q_{i}: |
in LP, the i-th minimum planning constraint or its corresponding artificial activity |
r: |
interest rate per period of length 1/q years, equal to an annual interest rate i of (1+r)^{q} - 1 |
R: |
depending on context, rainfall, or net return, or an annual payment amount that continues in perpetuity and thus has a PV of R/i, or the income diversity ratio, equal to (S R_{i})²/S R_{i}² where R_{i} (i = 1 to n) is the income from the i-th activity and 1 £ R £ n for R_{i}³ 0 |
R_{i}: |
income from the i-th activity |
R*: |
any nominated value of net return R |
RN: |
random number |
Rp: |
Rupiah; Indonesian unit of currency |
Rs: |
Rupee; Indian, Pakistani and Sri Lankan unit of currency |
RTC: |
index of relative time-concentration of annual production or income of a product, calculated as the CV of the product's production or income pattern as a fraction of the corresponding CV for a perfectly concentrated product |
RTD: |
index of relative time-dispersion of production or income, calculated as 1 - RTC |
S: |
the number of species or activities in a farm system; used in calculating the DI of a farm system |
SD: |
standard deviation, calculated as the positive square root of variance |
SP: |
simplified programming |
SV: |
the salvage value of a capital item |
t: |
depending on context, ton(s) or tonne(s) |
t: |
time, e.g., year t, or the time-length of an activity |
TC: |
total cost, calculated as the sum of total variable cost and total fixed cost |
TDN: |
total digestible nutrients |
TFC: |
total fixed cost |
TGM: |
depending on context, the total gross margin of an activity, of an enterprise or of the whole-farm system; equal to TGR - TVC |
TGR: |
total gross return or total gross revenue |
TPP: |
total physical product, equal to Y for Y = f(X) |
TVC: |
total variable cost |
TVP: |
total value product, equal to (TPP)p_{y} |
U: |
a decision maker's utility function |
U*: |
the linear transformation of U, equal to aU + b with a > 0 |
UAE: |
United Arab Emirates |
U(X): |
a decision maker's utility function specified in terms of the variable X |
V: |
variance, calculated for a variable _{} for a sample of observations X_{1}, X_{2},...X_{n} |
Vt: |
the depreciated value of an item at the end of year t under the declining-balance method |
VC: |
variable cost |
vs: |
versus |
w: |
annual rate of inflation (w > 0) or deflation (w < 0) |
X: |
a variable or an input factor |
_{}: |
arithmetic mean of a set of sample observations {X_{i}}, i = 1 to n, on a variable X, calculated as _{} |
X_{1} = h(X_{2}/Y*): |
isoquant equation giving the locus of all combinations of two variable inputs X_{1} and X_{2} to produce a fixed level of output Y* |
X_{i}: |
depending on context, the i-th observation on a variable X, or the i-th input factor, or the level of the i-th input factor |
Y: |
depending on context, a product or the yield of product (or output) from a production process |
Y*: |
some fixed level of output Y |
Y = f(X): |
single-variable production or response function indicating output Y is a function of the variable input factor X |
Y = f(X_{1}, X_{2}): |
production or response function indicating output Y is a function of two variable inputs X_{1} and X_{2} |
Y = f(X_{1}, X_{2},...X_{n}): |
production or response function indicating output Y is a function of n variable inputs X_{1}, X_{2},...X_{n} |
Y = f(X_{1}/X_{2},...X_{n}): |
production or response function indicating output Y as a function of the variable input X_{1} when inputs X are held constant |
Z: |
in LP, the TGM of a farm plan or the opportunity cost of including a unit of an activity in the plan |
Z - p: |
in LP, for an activity, when multiplied by minus one, indicates the net increase in plan TGM to be gained by adding one more unit of the activity to the plan |
¶ Y/¶ X_{i}: |
marginal product of X_{i} in Y = f(X_{1}, X_{2},...X_{n}), i = 1 to n, or the first partial derivative of Y with respect to X_{i} |
D (.): |
a small incremental change in (.) |
D X_{i}: |
a small incremental change in the level of the variable input X_{i} |
p |
profit, equal to _{} for the single product activity Y = /(X_{1}, X_{2},...X_{n}); for multi-product situations, equal to TGR - TVC - TFC or, more simply, GR - VC - FC |
_{} |
for a variable X, the sum of the values X_{1}, X_{2},...X_{n} |
¥: |
infinity |
>: |
greater than, i.e., a > b indicates a is greater than b |
<: |
less than, i.e., a < b indicates a is less than b |