feature it diffusion and industry and labour market dynamics the emergence and rapid diffusion of information and communication technology is the most radical technological transformation of the last couple of decades and has had an enormous economic impact this bundle of four articles contains research that discusses major economic implications of the diffusion of it they focus on two main implications of it i networks and industry dynamics and ii it and workplace organisation the two sets of two articles contribute both original theoretical insights and new empirical results to these themes

the backward incidence of pollution control a dual approach abstract the backward incidence of pollution control is reexamined using the techniques of duality theory the simple geometry used establishes the results and clarifies them without the complicated mathematical manipulations required in earlier works thereby making the material more attractive for classroom presentation

an empirical equilibrium job search model with search on the job and heterogeneous workers and firms in this article we present and estimate a synthesis of previous equilibrium search models allowing for continuous distributions of workers opportunity costs of employment as well as firms productivities the model allows for on the job search and we assume that job offer arrival rates for workers are independent of their labor market state we derive the theoretical implications of these assumptions we provide simulations and we develop a semiparametric estimation procedure that we apply to a dataset of individual labor market histories

private capital flows capital controls and default risk abstract what has been the effect of the shift in emerging market capital flows toward private sector borrowers are emerging market capital flows more efficient if not can controls on capital flows improve welfare this paper shows that the answers depend on the form of default risk when private loans are enforceable but there is the risk that the government will default on behalf of all residents private lending is inefficient and capital controls are potentially pareto improving however when private agents may individually default capital flow subsidies are potentially pareto improving

solving the feldstein horioka puzzle with financial frictions unlike the prediction of a frictionless open economy model long term average savings and investment rates are highly correlated across countries a puzzle first identified by feldstein and horioka 1980 we quantitatively investigate the impact of two types of financial frictions on this correlation one is limited enforcement w here contracts are enforced by the threat of default penalties the other is limited spanning where the only asset available is noncontingent bonds we find that the calibrated model with both frictions produces a savings investment correlation and a volume of capital flows close to the data to solve the puzzle the limited enforcement friction needs low default penalties under which capital flows are much lower than those in the data and the limited spanning friction needs to exogenously restrict capital flows to the observed level when combined the two frictions interact to endogenously restrict capital flows and thereby solve the feldstein horioka puzzle

unemployment and the backward incidence of pollution control abstract this paper reexamines the backward incidence of pollution control using duality theory for a two sector general equilibrium model in which the economy experiences large scale unemployment and perfect capital mobility with a sector specific rigid wage in the polluting sector in this context it is shown that with stricter pollution controls the wage rate in the nonpolluting sector rises while the common rental rate falls in addition stricter pollution controls are shown to have an uncertain impact on national income

sudden stops sectoral reallocations and the real exchange rate abstract a sudden stop of capital flows into a developing country tends to be followed by a rapid switch from trade deficits to surpluses a depreciation of the real exchange rate and decreases in output and total factor productivity substantial reallocation takes place from the nontraded sector to the traded sector we construct a multisector growth model calibrate it to the mexican economy and use it to analyze mexico s 1994 95 crisis when subjected to a sudden stop the model accounts for the trade balance reversal and the real exchange rate depreciation but it cannot account for the decreases in gdp and tfp extending the model to include labor frictions and variable capital utilization we still find that it cannot quantitatively account for the dynamics of output and productivity without losing the ability to account for the movements of other variables

migration and sovereign default risk abstract during sovereign debt crises countries experience persistent economic declines spiking spreads and outflows of capital and workers to account for these salient features we develop a sovereign default model with migration and capital accumulation the model has a two way feedback default risk lowers workers welfare and induces emigration which in turn intensifies default risk by lowering tax base and investment compared with a no migration model our model produces higher default risk lower investment and a more profound and prolonged recession we find that migration accounts for almost all of the lack of recovery in gdp during the recent spanish debt crisis

the growth of network computing quality adjusted price changes for network servers in this paper we investigate the evolution of quality adjusted prices for servers motivated by two facts first the productivity acceleration in the us economy since the mid 1990s is closely linked to spread of information technology of which networked computing is a large component second the growth of network computing itself has been fostered by the rapid growth in the quality and quantity of the network server market like pakes 2003 analysis of the pc market we show that our preferred version of the hedonic price index complete hybrid fell much more rapidly than the standard matched model price index the hedonic index fell on average by about 30 per annum compared to 17 p a for the matched model this difference is mainly due to the selection bias in the standard matched model price index due to the exit of obsolete models which would have had the fastest price falls

wage subsidies and distortionary taxes in a mobile capital harris todaro model in prescribing policy to eliminate or mitigate the effects of labour market distortions some form of wage subsidy is usually among the highest ranking options rarely is the source of revenues for these subsidies treated as an explicit issue this omission has special significance for the harris todaro h t model of the labour market since the policy most frequently recommended whether capital is sector specific or intersectorally mobile is an across the board wage subsidy 2 this effectively eliminates the possibility of taxing one subset of sectors rather than subsidizing its complement an option often favoured by those theorists who concern themselves with revenue considerations the next section of this paper sets forth the model of a small open h t economy with mobile capital that is the basis for this analysis section ii re examines three wage subsidies on manufacturing wages on agricultural wages or on both sectors assuming that resources for the subsidies are raised by an across the board tax on profits this is in the tradition of cordenfindlay and we replicate their results though stating them in more precise form so that we might have a standard for later comparison the subsequent sections examine the effects of these subsidies on unemployment and resource allocation if they are financed by a tax on profits in the manufacturing sector section iii or by import tariffs section iv owing to the second best nature of the h t model it will be demonstrated that taxes normally considered distortionary in their own right can be superior to an across the board tax if revenues are constrained and can be very useful instruments if it is the variety of policy tools that is limited section v concludes with a ranking of the various subsidy tax packages

what happens when agent t gets a computer the labor market impact of cost efficient computer adoption this paper offers a model of how computer technology has changed the labor market demonstrating that wage differentials between computer users and non users are consistent with computers first being introduced in high wage jobs following cost efficiency furthermore skill upgrading occurs following a reemphasis on non routine tasks after adoption the model also reveals that neither differences in computer skills nor complementary skills are needed to explain wage differentials between users and non users skill upgrading and the changing organization and intensity of work finally the predicted effects on the wage structure are consistent with empirical evidence

imperfect mobility of labor across sectors and fiscal transmission abstract our paper investigates the sectoral effects of government spending shocks and highlights the role of labor mobility our var evidence for sixteen oecd countries reveals that a shock to government consumption by 1 of gdp increases non traded value added by 0 7 of gdp and generates a decline in traded value added the value added share of non tradables rises by 0 35 of gdp thus implying that the reallocation of resources accounts for 50 of the sectoral fiscal multiplier consistently our estimates show that the non traded sector is highly intensive in the government spending shock and experiences a labor inflow the shift of hours worked toward the non traded sector is however subject to mobility costs which vary across countries when we explore quantitatively the sectoral effects of a shock to government consumption that is highly intensive in non traded goods we find that the model can replicate the magnitude of the rise in the share of non tradables we document empirically once we allow for both labor mobility and capital installation costs financial openness also matters as it further biases the demand shock toward non tradables to account for the cross country dispersion in the responses of sectoral shares we estimate empirically we have to let the degree of labor mobility vary across countries

the dynamo and the computer an historical perspective on the modern productivity paradox the dynamo and the computer an historical perspective on the modern productivity paradox author s paul a david source the american economic review vol 80 no 2 papers and proceedings of the hundred and second annual meeting of the american economic association may 1990 pp 355 361 published by american economic association stable url http www jstor org stable 2006600 accessed 08 12 2010 01 40

a reconsideration of hedonic price indexes with an application to pc s this paper compares hedonic to matched model indexes matched model indexes are averages of the price changes of goods that remain on sampled stores shelves since goods that disappear tend to have falling market values matched model indexes select from the right tail of price changes the bls can construct hedonic indexes that correct for this selection and are justified by standard arguments in an empirical study of pc s hedonics produce sharp price declines while matched model indexes are near zero also though there are modifications to hedonics that seem desirable they are not those in current use

urban unemployment and the gains from trade a welfare ranking of alternative commercial policies is constructed for the mobile capital harris todaro economy it is sh own that despite the presence of unemployment most noninterventioni st policies suggested by the competitive model of gains from trade ca rry over to the mobile capital harris todaro economy yet in contradi ction to the competitive model it is shown that all forms of trade i ntervention are not detrimental to welfare only those that reduce th e volume of trade are the export promotion policies so copiously fol lowed by developing countries are vindicated but their import substi tution policies are shown to be without justification copyright 1987 by the review of economic studies limited

default risk sectoral reallocation and persistent recessions abstract sovereign debt crises are associated with large and persistent declines in economic activity disproportionately so for nontradable sectors this paper documents this pattern using spanish data and builds a two sector dynamic quantitative model of sovereign default with capital accumulation recessions are very persistent in the model and more pronounced for nontraded sectors because of default risk an adverse domestic shock increases the likelihood of default limits capital inflows and thus restricts the ability of the economy to exploit investment opportunities the economy responds by reducing investment and reallocating capital toward the traded sector to support debt service payments the real exchange rate depreciates a reflection of the scarcity of traded goods we find that these mechanisms are quantitatively important for rationalizing the experience of spain during the recent debt crisis

financial integration and international risk sharing abstract conventional wisdom suggests that financial liberalization can help countries insure against idiosyncratic risk there is little evidence however that countries have increased risk sharing despite widespread financial liberalization we show that the key to understanding this puzzling observation is that conventional wisdom assumes frictionless international financial markets while actual markets are far from frictionless financial contracts are incomplete and contract enforceability is limited when countries remove official capital controls default risk is still present as an implicit barrier to capital flows if default risk were eliminated capital flows would be six times greater and international risk sharing would increase substantially

the division of labour worker organisation and technological change the model developed in this article explains differences in the division of labour across firms as a result of computer technology adoption changes in the division of labour result from reduced production time and improved communication possibilities the first shifts the division of labour towards generic structures while the latter enhances specialisation our estimates for a sample of dutch establishments in the period 1990 6 suggest that productivity gains have been the main determinant for shifts in the division of labour these productivity gains induced skill upgrading while in firms gaining from improved communication possibilities specialisation increased and skill requirements have fallen the rapid spread of computer technology has led to substantial changes in the division of labour and a shift in the demand for labour in favour of skilled workers mostly these changes have been accompanied by flatter organisational structures larger autonomy for workers or workgroups the application of innovative human resource management practices and so on there are also less typical examples where computerisation is associated with increased specialisation e g the rapid increase of call centres scripting of communication with clients and stricter procedures although the empirical relationship between information and communication technology ict adoption and organisational change has been well documented disagreement remains about the reasons why computerisation provides firms with incentives to change the structure of their organisation and the skill requirements of their workforce

the dynamic implications of foreign aid and its variability abstract the paper examines the effects of aid and its volatility on consumption investment and the structure of production in the context of an intertemporal two sector general equilibrium model calibrated using data for aid dependent countries in africa a permanent flow of aid mainly finances consumption rather than investment consistent with the historical failure of aid inflows to translate into sustained growth large aid flows are associated with higher real exchange rates and smaller tradable sectors because aid is a substitute for tradable consumption aid volatility results in substantial welfare losses providing a motivation for recent discussions of aid architecture stressing the need for greater predictability of aid these results are also consistent with evidence from cross country regressions of manufactured exports presented later in the paper

a note on the stability of the harris todaro model with capital mobility the present note derives the exact stability condition for the harris todaro model with intersectoral capital mobility where land is explicitly included as a third scarce factor in agriculture while the previous study by neary states the difficulty of deriving a clear cut result in such a case this note demonstrates that if capital and land are never technologically substitutes in the agriculture production neary s condition that the urban sector is more capital abundant than the rural sector becomes a sufficient condition for local stability in an important article in this journal neary 1981 considered the stability of the harris todaro model with intersectoral capital mobility among other things neary showed that when relative commodity prices are fixed and capital and labour are subject to constant returns to scale in agriculture an unspecialized equilibrium is dynamically stable if and only if the urban sector is capital abundant relative to the rural sector however in the original work by harris and todaro 1970 the fixed availability of land is included in the agriculture production function hence strictly speaking the stability condition quoted above is not for the original harris todaro model with intersectoral capital mobility on this point neary concluded that the introduction of a third scarcefactor land in agriculture greatly complicates the analysis and makes it impossible to derive simple and clear cut results the present note argues that a definite result can be derived if the normality property of factors of production which was utilized by rader 1968 and suzuki 1985 is assumed

stability of the mobile capital harris todaro model some further results a necessary and sufficient condition for stability is derived for the mobile capital harris todaro model of rural to urban migration in developing countries when land is a scarce factor in agriculture the stability condition when land is ignored that the urban sector comprising manufacturing industry and the urban unemployed be more capital abundant is no longer either necessary or sufficient for stability nevertheless this condition always enhances stability and it is sufficient though not necessary for stability in many circumstances e g when land is separable in production from labour and capital intuitive explanations of these conditions are provided excerpt

input output linkages and sectoral volatility why are some sectors more volatile than others this paper uncovers evidence of an empirical regularity in the us economy upstream sectors that are far removed from final consumers have higher levels of output volatility the relationship between volatility and upstreamness is not driven by sector size sector concentration trade openness or the level of aggregation at which sectors are defined rather the paper shows a stronger link between upstreamness and nominal output volatility than with indexes of real output volatility aggregate exports at the national level also reflect the empirical regularity of higher volatility with upstreamness export volatility is higher in economies with trade portfolios dominated by upstream sectors on average reducing the upstreamness of exports by 1 also reduces aggregate export volatility by about 10 the pattern of higher volatility for upstream sectors is explained with a model of demand shock transmission between sectors

labour turnover cost and the curious properties of the mobile capital harris todaro model abstract as corden and findlay 1975 have shown the mobile capital harris todaro model has certain curious properties viz that capital accumulation unambiguously increases unemployment whereas labour force growth reduces unemployment in this paper we show that introduction of labour turnover cost in the manufacturing sector dampens the above paradoxical results on one hand and strengthens the interesting properties of the model on the other

the terms of trade the real exchange rate and economic fluctuations this paper examines the relationship between terms of trade and business cycles using a three sector intertemporal equilibrium model and a large multicountry database results show that terms of trade shocks account for nearly one half of actual gdp variability the model explains weak correlations between net exports and terms of trade the harberger laursen and metzler effect and produces large and weakly correlated deviations from purchasing power parity and real interest rate parity terms of trade shocks cause real appreciations and positive interest differentials although productivity shocks have opposite effects the puzzle that welfare gains of international asset trading are negligible is left unresolved copyright 1995 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

sovereign default and capital accumulation i introduce endogenous capital accumulation into an otherwise standard quantitative sovereign default model in the tradition of eaton and gersovitz 1981 and find that conditional on a level of debt default incentives are u shaped in the capital stock the economy with too small or too large amounts of capital is likely to default in addition to an excusable motive for default in line with grossman and huyck 1989 our model also predicts an opportunistic motive for default in line with kehoe and levine 1993 the model predicts the opportunistic motive for default because 1 capital is used as a consumption insurance vehicle during autarky after default 2 installed capital within the border cannot be seized by foreign lenders and 3 our model does not use an ad hoc output cost of default which only penalizes default in high income states the two different motives for default allow the calibrated model to generate defaults in good and bad times in simulation with a frequency of 38 and 62 respectively this is consistent with tomz and wright 2007 s empirical finding that throughout history and across countries around one third of sovereign defaults occurred in good times when output is above trend whereas most defaults occur in bad times the model is calibrated to the business cycle moments of argentina and simulation results show that the model matches business cycle facts regarding emerging economies along other dimensions moreover simulation results show that default in good times occurs 1 after the economy has accumulated a significantly large amount of capital and 2 when the economy faces a modestly good shock both of which reduce the value of external borrowing but increase the value of staying in autarky on the other hand around defaults in bad times the model economy displays typical v shape economic dynamics with a collapse in absorption upon default especially investment aggregating quarterly data from the model into annual frequency is found to overestimate the fraction of defaults in good times around twofold

the backward incidence of pollution control in a rigid wage economy abstract the backward incidence of pollution controls onto the polluting and nonpolluting industries is examined in a two sector rigid wage economy characterized by unemployment in both the short run and the long run as expected more restrictive pollution controls result in contraction in the polluting sector and expansion in the nonpolluting sector somewhat unexpectedly national income may rise with stronger pollution controls if the polluting industry is relatively capital intensive

on the harris todaro model with intersectoral capital mobility n b professor neary was based at trinity college dublin when this article was first published the full text of the article is not available in ora at this time citation neary j p 1981 on the harris todaro model with intersectoral capital mobility economica 48 191 219 234

urban unemployment and non immiserizing growth abstract one purpose of this paper is to show that in the harris todaro economy economic expansion can not be immiserizing another purpose of this paper is to examine the implications of economic expansion for urban unemployment as well as sectoral outputs for the case of non neutral technical change finally it is shown that a damaging property of the harris todaro model that capital accumulation causes unemployment to rise whereas labor growth causes it to fall is at least partially rectified by the incorporation of land as a scarce factor in the agricultural sector

revolutionary effects of new information technologies in markets with imperfect information and heterogeneity the information technology affects the rate at which agents meet which affects the distribution of production technologies across firms multiple equilibria may arise because the reservation utility and the lowest production technology in use affect each other the adoption of novel information technologies may then entail a revolution in the sense of a move from an inefficient to equilibrium inefficient production technologies are swiftly moved even in sectors where the new information technology has only recently been introduced the results apply to consumer products labour intermediates and institutions royal economic society 2006