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Uncertainty treatment in input-output analysis

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Monetario Centroamericano' (see van Tongeren and Magnus, 2012, p.278). This<br />

paper also presents for the first time an empirical application to a large dataset of<br />

Guatemala (2500 variables). Thus, the Bayesian method, similar to the conventional<br />

national account<strong>in</strong>g approaches, deals with 'reconciliation' or '<strong>in</strong>tegration' of data, but<br />

differs from the last <strong>in</strong> several respects. 'First, all conditions of conventional estimates<br />

are formalized: identities are explicitly <strong>in</strong>cluded and ratios are <strong>in</strong>troduced as priors;<br />

second, reliabilities of data and ratio values are reflected <strong>in</strong> well-def<strong>in</strong>ed prior variation<br />

coefficients; third, the system is simultaneous rather than sequential; and f<strong>in</strong>ally,<br />

updat<strong>in</strong>g the system when new <strong>in</strong>formation becomes available is easy and fast, and<br />

does not require changes <strong>in</strong> the compilation method' (van Tongeren and Magnus,<br />

2012, p.278). In addition, '[t]he method also facilitates the simultaneous use of <strong>in</strong>dicator<br />

ratios <strong>in</strong> compilation and <strong>analysis</strong>' (Magnus, van Tongeren and de Vos, 2000, p.347,<br />

emphasis added). For IO <strong>analysis</strong>, the implication is that the estimated supply and use<br />

tables from the Bayesian approach will have reliability <strong>in</strong>tervals element-wise, and thus<br />

can be readily used <strong>in</strong> subsequent <strong>analysis</strong>, e.g. sensitivity <strong>analysis</strong>. Or alternatively,<br />

the method itself can be used, alone or <strong>in</strong> comb<strong>in</strong>ation with exist<strong>in</strong>g ones, <strong>in</strong> order to<br />

construct IO tables, aga<strong>in</strong> with uncerta<strong>in</strong>ty values attached to each element. Such an<br />

attempt is already made by Lugovoy, Polb<strong>in</strong> and Potashnikov (2014) who update IO<br />

tables for selected EU countries and SUTs for Russia us<strong>in</strong>g Bayesian methods. Their<br />

experimental results and comparisons with other exist<strong>in</strong>g updat<strong>in</strong>g methods confirm the<br />

usefulness of such approach.<br />

The problem of balanc<strong>in</strong>g IO data from the Bayesian perspective is considered by<br />

Rodrigues (2014). The author states that consider<strong>in</strong>g all available <strong>in</strong>formation <strong>in</strong><br />

deal<strong>in</strong>g with the data balanc<strong>in</strong>g problem implies account<strong>in</strong>g explicitly for the first and<br />

second moment constra<strong>in</strong>ts that <strong>in</strong>clude prior <strong>in</strong>formation about the values of the data<br />

(best guess) and their uncerta<strong>in</strong>ties. Rodrigues (2014) then derives an analytical<br />

solution of the data balanc<strong>in</strong>g problem by application of cross-entropy m<strong>in</strong>imization<br />

subject to the first and second moment constra<strong>in</strong>ts, and shows that the conventional<br />

data balanc<strong>in</strong>g methods, such as generalized least squares, weighted least squares<br />

and biproportional methods, are particular cases of the proposed method.<br />

Rickman (2001) presents a Bayesian <strong>in</strong>tegrated IO and econometric model of the state<br />

of Oklahoma. Compar<strong>in</strong>g seven models <strong>in</strong> terms of their performance <strong>in</strong> forecast<strong>in</strong>g<br />

<strong>in</strong>dustry employment, the author, for example, concludes that '[o]n average, a Bayesian<br />

model produced the lowest MAPE [mean absolute percentage error] across the thirty<br />

employment sectors and five forecast horizons' (p.241).<br />

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