@misc{Górski_Tadeusz_A_2009,
 author={Górski, Tadeusz},
 volume={82},
 number={1},
 copyright={Rights Reserved - Free Access},
 address={Warszawa},
 journal={Geographia Polonica},
 howpublished={online},
 year={2009},
 publisher={IGiPZ PAN},
 language={eng},
 abstract={An important source of risk in agricultural production is the variability to crop yields reflecting irregularly changing weather. This variability may be described as a stochastic process that has a function of density. Analyses of historical data on crop yields reveal that the function of density changed from right-skewed to left-skewed, along with increasing mean yields. All examined yields of crops cultivated recently in Poland demonstrate the left skew, which does not diminish with the aggregation of acreage. A fairly good approximation of the probability distribution for actual yields may be obtained using the log-normal distribution with an inverted abscissa.},
 type={Text},
 title={A probability distribution for crop yields in Poland},
 URL={http://www.rcin.org.pl/Content/55501/PDF/WA51_74830_r2009-t82-no1_G-Polonica-Gorski.pdf},
 keywords={crop yields, density function, log-normal distribution, area aggregation, scaling of variance},
}